I think what a lot of people are missing in this thread is that gender fluidity and "trans-" has only very recently been introduced to our culture on a noticeable scale. Yes, since the beginning of human civilization there have been cases of people identifying as a different gender than their biological sex, but it's only very recently (in a relative sense) that we've begun to accept and understand it. Right now there's a struggle between generations, the older of which is accustomed to the "two gender" model while the younger has adopted this "many gender" model. Most of the people on this site are of this younger generation who themselves are still in the infant stages of understanding this model due to being raised by the older generation who taught them a different perspective.
Tl;Dr I'll wager it's going to take at least 20-30 more years before this new model becomes the "norm"
Apologies if this is scattered or redundant, I've been drinking and I have two kids under two and thus haven't slept in months :)
Also ilu all