In the case of JKR that talking point kind of sailed on. Nobody really cares if you enjoy something second hand or where the money and interest played out years ago. The books, the old movies, the merch you picked up at a garage sale...

Problem is when you support the latest and greatest newly licenced thing that lines her pockets with cash because she is USING that cash to do direct damage to the community. She's been financially backing anti-trans groups and lobbying in the UK. Just ONE of her little go fund mes was chipping in a 700,000"£ donation to the lawyers who got gender recognition certificates made worthless in the UK Supreme Court. Ticket sales to events, merch deals, video game titles, remakes... It propells demand which means a nice big chunk of that coin passes right through her pockets and right into directly funding her hate and her fans go on to brigade trans support spaces which often are necessary emergency mental health support for weeks after a big release online. More than one suicide can be laid at the feet of these mobs.

The difference between that and Kevin Spacey is at least he's moldering quietly.