The dynamic of social interactions is really quite simple. Anyone who doesn’t approve of bad behavior ought to report it. Anyone who doesn’t report bad behavior is complicit by allowing it to continue and doesn’t get to complain about it. If you want to play the game but don’t like the toxicity, then report it. If you don’t report it then the behavior continues and you have no right to complain about it. If you quit, then you escape the toxicity, hit Blizzard in pockets where it hurts, and leave the bad players and the players that do nothing about them to suffer in a garbage community with each other.
Don’t press for proactive policing in games because it doesn’t work. The players are the ones that have to experience the game in whatever state it’s in, so if they let it go to “trash,” they’ll have no choice but to change their behavior, make changes and just suffer the effects of their actions and inactions, or quit. Let reality sort out the trash.