I'm really sorry about all the shit you're seeing in this thread, anon. Saying "It's just like het" is a time-honored way for fans to dress up their reasons for not liking any type of queer fic as being very smart and important. They've said it about m/m with two cis guys for forever. But it doesn't mean anything. Anything can be "like het" if you want to see it that way, and these types do. (I read both het fic and het romance novels as well as all kinds of queer stuff, and let me tell you, the favorite target for being "like het," the classic seme/uke dynamic, is nothing like a het romance novel. Typical romance novel heroines' personalities are more like the "seme" than the "uke" if anything.) Despite claiming it's not just the PIV that makes it like het, I doubt they could really give a concrete explanation about what does make trans m/m fic like het.

They should take the advice they give all the m/m shippers they assume are straight white girls, and just admit they don't like to read about vaginas. It's okay to just not like to read about vaginas! They don't have to pretend there's a deep reason for it!