not to defend assimilate, but I sorta get the whole "people pretending to trans IRL" cause I saw it when my daughter ran her highschool's LGBT club.
There were two kids in there that were definitely trans. They took it seriously and it wasn't "man in a dress" trans, I mean if you knew them you knew that they were damned serious about it. Then there were a bunch of other kids that decided they were "gender fluid" and treated it like a fad. Changing their gender as they wanted, naming themselves after their favorite anime characters and such one week they'd get all pissed if you called them a guy, the next you'd be crucified for calling them a girl. Of course, they're teens and we all did stupid stuff in our teens but I can see where the criticism comes from. I don't think it's common place, and it's a stupid thing, but I can't say I don't understand when people say "some people pretend to be trans" because I've certainly seen it.