Fascist femboys, autogynephilia, and flattering narratives
Among those who believe autogynephilia is real and the primary explanation for many or most trans women's transitions, there are a few typical replies to the common objection from trans woman, the obvious "No, I don't get off on being seen as a woman, that's weird that you would think that." The most common is some form of the following, in its most sympathetic framing.
"I'm sure it seems like that to you, but humans aren't always aware of the real reasons they do things, and commonly tell themselves more flattering narratives to explain their decisions and feelings post facto. In fact it is likely for autogynephiles to be in denial of their own autogynephilia."
More typically, people are less polite and say something more along the lines of, "Of course you're lying about being a pervert, you're a perverted man."
I'm not going to write a refutation of the concept of the autogynephile as a meaningful category here, others have already done so to a level I find satisfactory. A compact summary of my opinion on the matter is that anyone who takes Ray Blanchard seriously as a scientist after the mockery of good scientific statistical practice and research ethics that is the original autogynephilia study should be laughed out of the discipline, and subsequent attempts to prove its existence have not been substantially less laughably shit.
Perhaps surprisingly given the generally hostile presentation of autogynephilia as an explanation for gender feelings and gender dysphoria, there nonetheless are a number of self-identified "autogynephilic men." Those include people who have actually socially or medically transitioned (and intend to continue to present as women, stay on HRT, etc.) who nonetheless maintain that they are not in fact women and are in fact men who have transitioned because they get off on themselves as women, as well as people who have perhaps tried HRT, but didn't stay on it, or maybe made no real attempt to transition at all, or have since gone back to presenting as men in their public lives, i.e. detransitioned.
To most people this seems like utter insanity. And they're not wrong. You tend to end up with "friends" who not infrequently want you dead or institutionalised, and certainly not free to do your own thing, and are happy to say as much behind your back and often to your face. You earn the enmity of trans people, because you're feeding into this hostile narrative and are generally aligning yourself certainly rhetorically and often politically against the rights of trans people, regardless of your own individual beliefs.
@TracingWoodgrains, a former friend, has respect for some of these people, saying:
Perhaps it reflects a failure of imagination on my part, but I find Saotome-Westlake's thoughts much easier to absorb and understand than those of most trans or trans-adjacent people, because his theory of reality seems to cleave closest to my own understanding. I don't believe he speaks for anywhere near the experience of all trans people, but I do believe he is going through the same fundamental set of internal experiences as many who decide to transition as a result. That his stance does not flatter himself, too, makes it easy to believe.
It would be much, much easier for Saotome-Westlake to embrace the same frame as most put around that experience: gender euphoria as an indication that, in some fundamental way, he is and has always been a woman. Transition in order to capture the immutable essence of who he is. So forth. Being trans is unpopular enough; by framing himself the way he does, he loses not only those who look at every trans person as a potential sexual predator or freak—who would certainly not be mollified by an explicit admission that much of his own motivation towards experiments with transition is inextricable from sexual feelings—but also those who fully embrace the frame that they have always been women, just waiting to understand it.
Because Saotome-Westlake is a potential malefactor in his own narrative, it seems like he must continue to hold that belief out of a strong sense that it is true and that he wants to believe the truth, even if it's unpleasant for him personally. This isn't unreasonable, certainly in the general case it's a fairly likely explanation for someone to have beliefs that are otherwise inconvenient. But I think Trace, for a number of reasons, not the least of which being his own bigotry, completely misses the mark here.
Femboys
To explain what Trace is missing, we need to talk about femboys, and specifically the attitude younger, online right-wing men often have toward them. People often express surprise and confusion tht a subculture which hates gay people, trans people, and women, would be very openly interested in having sex with feminine men.
This is a real thing. Fascist femboys are oddly common and oddly popular with other young fascists. Sometimes the "femboys" are cis women with short hair who they imagine as teenage boys they'd have sex with back in ancient Rome. It's strange, to say the least.
Men who will deride a man as "gay" for being vocally in love with a cis woman they are married to will thirst after a young transfem in an Amazon Basics skirt who clearly is on HRT so long as said transfem says they are a femboy and not a trans woman. Right-wing men will fetishize the fuck out of characters like Astolfo the Fate series, Felix/Ferris from Re: Zero, and Bridget from Guilty Gear. 
Meanwhile this (linking to avoid embedding a trans woman wojack inline) illustrates how they view actual trans women. So what gives? Are they very committed to some concept of truth about gender and sex and see trans women as liars? Are they gay or bi and in denial about it? Well I think the latter is definitely sometimes true (cough cough, Nick Fuentes) and I think all of it is downstream of weird fucking misogyny, but I think the real answer isn't that they're gay, it's that they're straight (or bisexual), they are attracted to transfeminine people (as many straight and bisexual men are, or we wouldn't be one of the most popular porn categories), they're scared of cis women as much as they hate them, and trans women are fundamentally threatening to their worldview in a number of specific ways.
How? Well the obvious reason is because we're insane from their point of view, even treacherous. We are class traitors, moving from one category to the other, voluntarily (in their eyes, no matter what we say) joining the lesser sex, the enemy, and then quite often advocating for our rights and those of women in general. This is in general one of the reasons I think society is weird about trans women in ways it's not as weird about trans men, but it's particularly sharp for young misogynist reactionaries. They of course especially take offence at the idea that people might consider us brave for doing so, because they believe women currently have the upper hand in society, that the West as it is presently is degenerate and feminised, and so trans women are traitors seeking the easy way out, giving into what (((they))) want for all men. Yes, they believe or seem to believe both of these things at once, nobody should expect fascists to be coherent or consistent intellectually.
Society is of course also often deeply weird about trans men, but in quite different ways, because trans men poke at a different set of fundamental things people usually believe about gender and sex, but it's at least more understandable for a "woman" to want to be a man, both from a misogynist point of view and from a utilitarian point of view.
And so they end up in this weird dynamic with femboys. Feminine enough to be conventionally hot, "happy" to be sexualized, and generally compatible with the kind of relationship a young guy who doesn't want to marry (the way a cis woman of similar age and political persuasion would likely want, and she might not put out, either, want to save it for marriage) is interested in. 
On self-image
"Liking femboys is straight actually" is thus, if not a flattering narrative, at least a psychologically safe one. And for said femboys, those who do socially and/or medically transition in some way (as a nontrivial number clearly do), those who one could reasonably argue are trans women by another name, why accept a subordinate and fetishized position in a subculture that will never see you as anything other than a sex object, much less a woman, and will discard you when you age and "twink death" occurs? Well because you're probably very racist and again it's psychologically easier to stay in your community and express yourself in the ways that it allows than leave it and reconsider all your political views. And you'd have to hide your bigotry and history in order to not get run out of communities of trans women.
So why would someone adopt a framing that paints themselves not just as possibly gay (derogatory) and feminine (derogatory) the way the fascist femboy does, but as a potentially deceptive fetishist?
Rationalism
Well, imagine you're part of an online subculture where one of the highest virtues is "biting the bullet", looking hard truths in the face, accepting them, and then figuring out what to do from there. I am (or was) a member of said subculture and still adhere to many of its virtues, and some of its vices (like writing massive walls of text). The simplest form is this quote:
“That which can be destroyed by the truth should be.”
― P.C. Hodgell, Seeker's Mask
But it gets quite a bit of repetition in various forms in the Sequences:
If the box contains a diamond,
I desire to believe that the box contains a diamond;
If the box does not contain a diamond,
I desire to believe that the box does not contain a diamond;
Let me not become attached to beliefs I may not want.― Eliezer Yudkowsky, The Meditation on Curiosity
There's even an AI-generated sea shanty-alike made out of the above:
It's kind of an earworm, I'm very sorry. Regardless. Being someone who bites the bullet at personal and emotional cost is something that other rationalists and people culturally adjacent to rationalism would approve of, as TracingWoodgrains does of Saotome-Westlake (also known as Zach M. Davis, he finally dropped the pseudonym), and one or two others within or near the rationalist subculture who self-identify similarly. This is especially true when you are placing yourselves in opposition to the kind of online progressives that Scott Alexander once compared to Voldemort, though the line has since been removed.
Actual Voldemort, of course, hates trans people.
Amusingly the above remains true whether I am referring cheekily to J.K. Rowling herself, to the probable beliefs of the character she made, given his politics, or to Ralph Fiennes, the actor who played You-Know-Who in the Harry Potter movies.
And I have unfortunately been subjected to enough of Zach M. Davis's to know that he is a misogynist with right-wing politics, and is pretty damn racist to boot.
There but for the grace of Yud
Reading his writing on gender and his relationship with it, there's a lot about Davis that's familiar to me as someone with a somewhat similar background, adolescent intellectual proclivities, and online life, just a couple years younger than him. I similarly did not even think of the possibility that I was transgender growing up, though in retrospect I clearly showed signs. In my case I was even less aware of trans people than Davis, having spent a chunk of my childhood in Congo and having parents who took some steps to shelter me from hearing too much about gay people in elementary and middle school (I would hazard a guess that Davis is Jewish). And like Davis, I didn't see the classic "born in the wrong body" narrative in myself either. Unlike Davis, I had a girlfriend all the way through high school and into university, and other female friends and acquaintances, despite being an awkward fucking nerd. Davis, well, I'm reading between the lines here a bit, but it seems like he had few friends in real life at all, and few of those were women. Much of his writing about his past "feminist" self (whose beliefs he repudiates) reeks of a lack of experience with actual women, and an obsession with a pedestalized image of femininity. This is understandable in some ways, but I think it also shows where and why we start to diverge so sharply.
One of his first encounters with transfeminity in media was, perhaps unsurprisingly for the era, Ranma 1/2. He got into the sexualized gender transformation stuff quite early, presumably having more unfettered access to the internet (where through most of high school my options for internet access were school computers or the family computer in the living room). I got into that sort of thing at some point (and of course that makes me an autogynephile, regardless of anything else about my sexuality, that I got turned on while thinking of myself having breasts is sufficient), but it clearly never became the kind of preoccupation for me it was for him. Honestly for me growing up, masturbation while viewing or reading erotica itself was more than enough transgression for this teenage (at the time) Baptist.
When I got into transformation narratives, I was usually much more interested in the kind like the webcomic Misfile, which, if you remove the supernatural elements and framing narrative, was essentially just a good story about the challenges of being a teenage trans boy. When I did read (or watch) something primarily erotic and trans-adjacent, it was usually something similarly grounded, which didn't reek of homophobia and misogyny the way a lot of "sissy" fiction (and trans erotica targeted at cis men in general) does. Davis remained thoroughly obsessed with the magical transformation, and quite terrified of the messy realities of being transgender. And as he shed his feminism and became much more obsessed with "biological reality", this continued.
Because he views men and women as fundamentally different on every level, "becoming" a woman would be a destruction of himself, after a fashion. He's afraid that he'd lose his love of mathematics and his skill at it, along with major aspects of his systematising worldview, as those are "male" traits that a "real, biological woman" version of himself would not have. And so on. I'm not going to name this for what it is because honestly it's so obvious as to be redundant.
And that's the biggest divergence. I think biology is real. Men and women are different, though we are also similar, and the differences are not always what we expect, and we are all people, with lots of ways to be ourselves. There are things medicine cannot change about me in service of transitioning my sex, nor would I necessarily want them to. Because while the target body for Davis is idealised feminine perfection, I never really wanted that. I wanted and want to be both, of both worlds and neither, physically, as I am psychologically. And of course that makes my preferred reality easier to achieve in some ways given current technology and medicine, but even if I were a binary trans woman who wanted to get rid of my penis, and even if I was less naturally androgynous, I can (and did) take a step back, consider the risks, the benefits, and what the prospect of my own sanity is worth, and see that for me there was only one option that lead to the potential for my flourishing, rather than my languishing.
But since he cannot accept a messy, imperfect reality where he might not pass and might have surgical complications and cannot accept that, in spite of that possibility, and even if some of his fears were to come to pass, it might still be worth doing for his own sanity, he is incapable of taking the required steps to maybe be actually happy.
And so, being thoroughly embedded in a culture that rewards accepting "hard truths", especially when they go against liberal "social justice" consensus, I don't think it's much of a leap to suggest that Davis's self-narrative around autogynephilia is far more comfortable for him than the prospect of being a (cringey) trans woman, one of many in the Bay Area, particularly because his other political beliefs (see above) don't exactly endear him to the average trans woman in tech, so it's not like he'd be gaining a new community. Besides, what he is now is far more special. He's an iconoclast, standing against the anti-science consensus that wants to deceive you about biological reality! He is even going against the first Rightful Caliph himself (itself a virtuous thing for a rationalist) in this! He is also conveniently protected from a lot of transphobia by virtue of presenting as a guy in his daily life most of the time. Because, as you can see from the femboy stuff, while people don't exactly hold "weird feminine guy who crossdresses" in high regard, that doesn't mean they're better if you ask for she/her pronouns.
Side note:
Eliezer is surprisingly based re: trans people, considering everything else about him, and has a better track record on predictions regarding the relevance of transness in reactionary political narratives than he does on AI.
Stories and Categories
There's a very strange way in which it's easier to "admit to being a pervert" than to admit that you're a woman, given certain ideological and cultural parameters. The former is a category that exists, that's normalized for "men" on some level, even protected if you're in the right circles (as we observe with Jeffrey Epstein), even if it's not a morally laudable one. The latter is a category error, a thing that cannot be, should not be, and to the extent that it is, is just a special case of the former, thus sayeth hundreds of years of social programming weighing down on you.
In some ways I had a much easier time emotionally than many figuring my gender/sex out (once I realised there was something that I probably needed to figure out) because I'd never seen Ace Ventura, or Silence of the Lambs, or watched Jerry Springer. My sheltered upbringing kept me ignorant, but that ignorance meant that I had hardly encountered, much less had time to internalise, the common narrative of transfemininity as disgusting, deceptive, and perverted, and so when I encountered transfemininity for the first time in my late teens or early adulthood, it held little fear for me, for as much as I'd internalised that there was something wrong with the feelings I'd had since puberty, as much as I was ashamed of them, I'd never attached that shame to transness, because I'd hardly had a chance to connect the two, being essentially unaware of the latter, and my own feelings being quite a different shape than either the classic binary narrative, Davis's experience, or other common portrayals. It still took a while to really work through the possibility, but my worry at the time was partially that I was appropriating the real thing because I wasn't suffering enough in the right way from my gender/sex, all while not realising that my suffering was in fact from my gender/sex. Regardless, I didn't have the chance to tie myself in knots about it for over a decade in nearly the same way, and once I figured it out, I knew that I had to do something now or I might never, and so I did, because like my parents, I might be cautious in a lot of ways, trepidatious, or anxious, but once I decide something needs to be done, I'm on the metaphorical (or literal) plane to Africa as soon as can be reasonably arranged.
I realise that I've focused on one specific person here, more than the general case, but this is the one who was the example given of a supposed unflattering self-narrative that is therefore more likely to be truthful, and Davis is the self-identifying autogynephile who has gone into by far the most detail about their own experience and mindset. Plus, given that the both of us have been around rationalism since more or less before the beginning, we make a good contrasting pair. But this isn't exclusive to rationalists either, as the femboy phenomenon illustrates, and regardless I think it's an interesting exercise to actually examine Davis's self-narrative and think about the implications, and also finally get around to dismantling the racist ex-Mormon fox's terrible argument.