I was just called a "flat earther" by a "Gender Critical". It's quite funny because I've been thinking about how the study of oppression is often similar to something like astronomy in the sense that the scientist can observe their subject but can't directly affect it.
We can't study misogyny via an experiment where we put one woman in a world with misogyny and another woman in a world with no misogyny and see what happens, we just observe this world and come up with theories to explain it, theories that can be tested when new data comes in.
The "Gender Critical" theory (if it can be called that) is that your birth sex (or chromosomes, or gametes, or intended gametes (???)) determines whether or not you experience misogyny. OK, we can test that quite easily, and it explains misogynistic oppression for well over 90% of the population. Great.
One problem though, there's this specific category of people for whom it doesn't seem to work at all. The data that comes in from our sociological "telescope" is stuff like the gender pay gap statistics, and that tells us that, accounting for other marginalisations like race, sexuality, disability, there's around 1% of people who according to GC theory should be at the top of the pile but are actually right at the bottom.
Their theory cannot explain the observations that we see, so there must be something that their theory is missing. It's just like the Michelson-Morley experiment that disproved the existence of aether or Eddington's observation of light being deflected by the sun's gravity. The old theory cannot explain what we observe, so we need a new one.
We can try out a theory from Julia Serano that says that sexism actually has two forms: one that venerates masculinity and abhors femininity; and another that rewards adherence to the gender expression that society has decided is appropriate for your birth sex, and punishes deviation from that gender expression.
It follows from this theory that someone who was assigned male but has a gender expression that society has decided is "female" will be uniquely hurt by sexism twice over, by virtue of being at the intersection of these two forms of oppression. And that group is also precisely the group at the bottom of the gender pay gap statistics! Awesome, the new theory can explain the observations, so we adopt it going forward.
"Gender Criticals" are like adherents of Newtonian Gravity who not only refuse to accept that it has been experimentally disproved, but also go out of their way to disrupt further observations by smashing all the telescopes sensitive enough to measure the relevant phenomena and use their political power to close down University departments that believe in General Relativity Ideology. And yet they call me a flat earther.