I strongly recomend you watch Contrapoints on the topic - she goes into a wealth of detail.

When the fuss first blew up a few years back, I assumed it was just your standard thoughtlessly-insensitive old person with outdated ideas but no particular malice.

I was wrong. Holy hell.

JK doubled down again and again and again on her hatred for trans people, to a jaw-dropping degree. She is raving batshit insane on the topic.

And once you've watched through that, check out the Shaun video on her ethics and political stance. Again, it goes into detail, and it's not pretty.