I'm sure you get it, but to these idiots, how is he a hypocrite? There were so many men at the time who glammed it up but we're unapologetic womanizers and typical dudes in every other way.
Oh Stewardess? I speak troon.
The people who were in KISS presented in an unconventional gender non-conforming way and performed in a challenging outlandish manner. They just wanted to have fun with it, but right wing bigots accused them of being "Knights in Satan's Service" and a satanic, dangerous influence over children, damaging their innocence and encouraging ungodly, deviant, immoral behaviour. Those people also think that trans women are a threat to children and allowing gender affirming care for children and teaching kids about gender will damage the innocence of children and encourage deviant and immoral behaviour.
THEREFORE if they are now agreeing with TERFs they are trying to ally themselves with the very same people who wanted to ban them!
This obviously isn't true (I mean for one, if an actual member of KISS is saying this then obviously it's not the case) but that'll be the broad strokes of why they think the guy out of KISS is a hypocrite. Oh also they keep bringing up "Christine Sixteen" ("I don't usually say things like this to girls your age, but when I saw you coming out of the school that day. That day I knew, I knew, I've got to have you") so I guess they're pissed at sharing their turf.
About 10 years ago this might have been a groundbreaking thread. But "The Sex Determining Region Y Gene Can End Up On An X Chromosome" is something that's been repeated ad nauseum ever since the first twitter TRA with a Biology degree decided to tweet about it. "Sex Is Actually A Series Of Different Traits That Are All Separately Sexed" is a bit newer but again, is just a repeated argument at this point (and arguably isn't really a biological argument, since it's more philosophical - does a woman with 10 nmol/L serum testosterone have a "biologically male" testosterone level or does she have an excess of testosterone for a woman? You could probably argue each one, except also a woman with that much testosterone would probably have something seriously wrong with her body to have caused that).
I would be fully supportive of a mass karyotyping program so that everyone could learn their chromosomes, though. "You don't know my chromosomes!", "Did you experience a normal male puberty? If yes, then I'm betting my left arm that you're XY".