Probably because saying benign stuff like "there are only two genders" is considered transphobic by radicals.

There are (1) people like J.K. Rowling, (2) people like Kiwi Farms, and (3) people who can’t tell the difference between (2) and (3). (3) likes to use the word “transphobic” indiscriminately.

To be fair I don’t know if the people involved are complaining about (1) or (2) or both but they are using a word that I am putting in quotes.

See, this is exactly the kind of thread I would not want to see on Threads (or HN)

There's only ever one reason...