The thought that people aren't buying the game out of spite doesn't really occur to these types of people, since they tend to view things in a black-and-white way. Harry Potter fans that don't care about the alleged transphobia and anti-Semitic narratives? People who actually want to have fun with the gameplay? Impossible.
It's why there's so much emotional brow-beating. There is no evidence to actual transphobia or anti-Semitism present in the game, so detractors have to make up instances in which they do exist, then socially punish people who do not fall in line. For the hundreds of people who are deterred from publicly liking Rowling and purchasing the game because she openly states her beliefs (or have heard about her through the grapevine), there are thousands more who either aren't aware or absolutely don't care.
I do love the line where the author stays "supporting trans people is not asking a lot", ignoring the fact that the vocal trans community as a whole have been taking a mile when offered an inch of courtesy, and still demanding more.