They also aggressively went after fan-made variants and other content posted online, unlike almost any other miniatures/boardgame publisher. Lot of (ex-)fans upset about that.

I think that has in particular bothered older players, as traditionally, pre-GW, miniatures gaming was all very DIY, dominated by amateurs. GW turning it into big business and throwing lawyers around did not make many friends from that hobby old guard. There are still niches of the hobby where GW are not very popular, or just never talked about.