I think the problem is that it is hard to be a Potter fan without giving Rowling money. Her claws are all over the IP meaning that anything with the Potter brand is putting cash in her pockets. Not an issue in and of itself, apart from the fact that she is now known for wielding her money and power for all the wrong reasons. A couple of months ago, she set her lawyers on a random I follow on Twitter - he is literally just a normal guy who has a couple of thousand followers, and is best pals with a former colleague of mine. He also happens to be a gay guy and a trans ally. He quoted one of her tweets out of context and she threatened to sue him into next century, forcing him to delete the tweet and issue an apology. The combination of her astronomical victim complex alongside her obvious willingness to actually destroy the lives of genuinely powerless ordinary people with a click of the fingers is just disgusting to me.