There were troonbians back in the 70’s, one got beaten up by angry lesbians at a women born women music festival back then. There is a reason why women born women was a part of the radical feminist lexicon, they always had to deal with straight men in drag.
There was also a woman who raped gay men by deception during the AIDS era, she was a sick fuck who reveled in contracting HIV as it was validating.
I remember both of these things. During the AIDS crisis, it was pretty shocking to discover a bug chaser. Lesbians were mostly helping take care of the sick and dying gay guys, not raping them.
There have been a lot of incidents of MtF at women's festivals and gatherings, starting from the beginning really. The feminists during the 70s and 80s were the most angry about it as far as I know. And good for them.
Because traditionally they have been subject to the same kind of hatred from the same kind of people, who generally didn't distinguish between one variety of faggot and another. These people aren't big on nuance and don't really care why a man is in a dress or having sex with another man, he needs a beating. So they gathered together, to some extent, for self-defense. And then when marriage equality became a thing and the last major, federal level, overt legal discrimination against gays and in general people of non-hetero sexual orientations crumbled, their interests diverged.
This occurred alongside the sudden lack of anything major for the organizations centered around "LGBT" interests to do for fundraising or, really, even to justify their own existence as national organizations. Organizations ultimately take on a desire for self-preservation that is distinct from the interests of any group they claim to represent, and now the new frontier is troons and troonery, and the goal isn't equality but to push some pseudoscientific cult ideas onto the public and force the public to bow to them.
This is pretty close. There are things for organizations to keep doing- state by state, protections against workplace harassment or discrimination, getting conversion therapy banned, adoption rights allowed, those kind of things. The original LGB groups mostly focus on that stuff as much as they're able, these days.
The T were included just exactly as you say, because back then
any strangeness got lumped together, and the more people you've got signing a petition or marching at the mayor's office the further you'll get. But once you've stopped the main forms of hatred, it is obvious that their interests are not our interests, and in fact they're opposed in some cases. Conversion therapy is a massive issue, and pushing transition on young LGB people is just an offshoot of it. (I would include gender conformity as another interest T really promote that LGB people fight against.)
T also are notorious for dramatics, even back then it was known that any discussion that included them would devolve into nonsense. They've always been misogynist, too. Lesbians usually ran any kind of discussion, organizing or debate back then, just because they were calmer.