Earlier quoted context omitted.
"Probably because one of those two is a religious statement, while another one is a political statement." Why would biological facts be considered "political statements"? (assuming gender = biological sex, which is the usual usage from regular talk to identity papers throughout the world).
Judging from the last sentence, it seems like you're aware that the word "gender" as it's used nowadays often doesn't refer to biological sex, especially in the context of gender identity/expression. Setting aside the semantic argument, is there even anyone out there saying "there are more than two genders", and actually mean biological sex? What would they even mean by that? From what I can tell, anyone saying "ther…
The whole point of any expression is that (by definition) is subject to the decision (one may say the whims) of the person doing that expressing. On the other hand, sex is set in stone, no psychological change and no surgery can change it.
While you may not have heard anyone saying they are gender fluid as a result of their chromosomes, I counter with the fact that one of the most common claim of the genderfluid people and their advocates is that "sex is a spectrum", which has basically the same meaning.
Moreover, there are educated university professors which publicly claim Homo sapiens have more than just 2 genders https://www.youtube.com/watch?v=ij80qmJPhOc
For the record, I couldn't care less who people have sex with and what sex they believe they belong to