I have the same question. My intuition leads me to think that trans women would WANT to be considered different from biological women because trans women obviously face challenges that biological women don’t. If trans people want “transgender” to be a separate gender and don’t want a binary gender system, why are they so insistent on being considered “real men” or “real women”? JK Rowling gets a lot of hate and while I haven’t cared to follow anything she’s said, the idea of trans men not wanting to be called women is on par with cis men not wanting to be called women.
The entire thing is complicated as both biology and sociology play into it. I don’t believe either side is generally wrong or right; although, both sides absolutely go about it in the wrong way to some degree. I hate to lump everyone aside, but more and more the subject is becoming polarized and it seems futile to speak objectively about it. The thing is JK Rowling is not the one putting trans people in danger. It’s all the horrible people who attack transgender men and women for being who they want to be who put them in danger and who are to blame. JK Rowling didn’t put the sticks and the stones in their hands, it’s on them. (And yes, I am aware she is a very famous person, and her voice is heard very far so to speak.)