Realistically, the number of people seeing it specifically to spite SJW’s is in a tiny, tiny minority. But all they’re really doing is voicing the unconscious “will” of the masses, which is that everyone is unhappy with the direction Hollywood is going in and showing it with their wallets.
Sonic is a fairly by-the-numbers kids movie that successfully executes on everything it tries to do, but doesn’t aim any higher than it needs to. It’s the very definition of a baseline “completely adequate” movie, and the fact that it’s making this much money and getting this much praise heaped on it is more indicative of the state of Hollywood than the mindsets of the fans. In a healthy industry, the only notable thing about Sonic would be the fact that it’s a successful video game movie.