I always feel a little nervous getting into these discussions because of how Americo-centric they are. There doesn't seem to be room for those of us who don't share your social and cultural mores; no extension of understanding. And so offering opinions from a different perspective is sometimes met with hostility.

The main problem boils down to, as dattum says, how esoteric these subjects are. Short of having a formal education in them, most people won't understand or will misunderstand (coming from layman perspectives) what you're saying.

The chorus of "it's not my job to educate you" does play a serious role in this. It is your job to educate; if you really want to change minds then it's your responsibility to explain to people who don't have the benefit of your academic background.

made fun of me and my preferred pronouns of "xe, xir, xim," saying that they were pretty liberal and open minded, but they thought these alternate pronouns were goofy.

They are goofy. We have established personal pronouns in English and, basically, making new ones up is going to be seen, at best, as eccentric.

Again, I'm sure in certain academic circles in the US this is probably par for the course but not everyone has that background. Meanwhile, this...

wording women as "womxn,"

Is something that I would need explaining about. The only times I've ever seen the likes of "womyn" used are arguments about radical feminism.

For the most part, I do agree with what you're saying but at the same time you come off sounding self-righteous. That's going to get anyone's back up.

They care more about calling themselves "progressives" than actually getting shit down and actively working to dismantle oppressive power structures.

By the same token, in places like SRSD, I'm reminded of a scene from Life of Brian where the PFJ are drafting a condemnation of... well, it's been a few years since I've seen it so I can't remember the specifics. But the group becomes bogged down in terminology and argue over what to use. The closing scene of Brian hanging on the cross, only for the PFJ not to come and rescue him but to read a long-winded and ultimately pointless expression of commiserations and thanks for what he's done is probably a better example.

I realise it must sound awfully uncharitable but I would agree with the satirising of certain left-wing groups as being feckless and more concerned with appearing right than doing right.

There are issues on both sides of this.