“You are the gender you ‘pass’ as,” is confusing, since “A woman is someone who looks like a woman,” doesn’t mean anything unless I assume you mean “A woman is someone who looks like a member of the female sex.”
Are you proposing that the definition that makes the most sense is “A (woman|man) is someone who looks and acts like the (female sex|male sex).”?
Any trans-inclusive usage of the word “man” has the problem you’re describing.
Including both the female sex (trans-men) and the male sex (cis-men) in the definition of the word “man” necessarily means that men who are attracted to men are not homosexual.
I see I’ve skipped a step in the original comment.
I mean that the definition predicts the behavior because it predicts the felt sense. If someone says to me, “I am a man,” and I think they are using the word to mean “a deeply felt sense of being male,” I’d expect them to have a deeply felt sense that they’re male. Because they have said sense, I’d then expect a desire for HRT if they aren’t male.
So “I am a man,” predicts the male-sex sense which predicts HRT, if both the the definition of “man” is “male-sex sense” and the speaker is female.
The internal sense of one’s sex is an unseen variable. We can infer the value of this variable (male or female) given behaviors like seeking HRT or SRS. We can also infer that “man” refers to this unseen variable based on the relationship between the behaviors (HRT and SRS) and the usage of the word “man”. I think.
If “a (woman|man) is someone with a deeply felt sense that they are (female sex|male sex),” is the definition people are using, that would predict hormone replacement therapies, sexual reassignment surgeries, and a reported mismatch between someone’s gender and their sex. That usage seems to fit what we observe really well.
I’m eager to know if this is missing something. The next most likely thing people could mean, I think, is “A (woman|man) is someone with a (female brain|male brain).”
The words “man” and “woman”, in their most modern usage, seem to be a map-territory confusion.
Defining these words intensionally (in terms of other words) usually ends up circular. Defining these words extensionally (by pointing at examples) seems to give us a pretty simple intensional definition: “A (woman|man) is someone with a deeply felt sense that they are (female sex|male sex).”
Since people consider their brains to be their “real” selves, they may also think their internal sense of their sex is their “real” sex. This isn’t an explicit belief anywhere, but it shows up in the way people talk about it.
But your sense of your sex is not your sex. It’s a reference to your sex, and it’s part of the map. If your sense of your sex (your gender) doesn’t match your sex (your body), your sense of your sex is wrong. Maps that don’t match the territory are wrong.
Moving the word for “adult human females” to instead mean “Everybody with a felt sense that they’re adult human females” sets up a motte and bailey. The motte is “Gender is separate from sex,” and the bailey is “Trans people’s felt sense of their sex isn’t wrong.”
The only reason to redefine the word for adult female persons to include people who want to be adult female persons is to make it sound like people who want to be adult female persons are, in fact, adult female persons.
If someone is desperate to be the female sex, what comfort could they possibly get from being called women? What soothing magic do those syllables have except the false implication that the referent is somehow female?
I see people defending the re-definition of the word “woman” with something like “Words can mean what we like, and it makes trans-women less upset!” but I’ve yet to see someone explain why it would make someone less upset if definitions were indeed arbitrary.