> What would a "professional and politically neutral as possible" company, in your definition, do in this case?
* "Female"
* "Other (feel free to specify in the text field below)"
Or something along those lines, it's not that hard.
That said, it seems a very neutral approach to gender self-reporting is self-defeating (consider that, at least for bathroom laws in some US states), the very notion of something that's not on the assigned-at-birth male-female binary is itself controversial. I guess if your gender choices included "deconstruct the male-female binary" or something, that'd be overtly political, but at least in this political climate just acknowledging the existence of some people seems to be a political act. (one I'm in favor of, fwiw, but I'm one of those people that argue that being "apolitical" is just cover for being politically in favor of the status quo).
Anyway back on topic:
Open field text boxes come with a practical cost of being much more difficult to aggregate, and let's be honest, the gender data is probably not important enough for GitHub to expend too much energy on. The more costly you make the data to mine, the less likely that the data will be used effectively.