It took 4 IRL years for Sylvanas to get punished. People got mindbroken into being slobbering morons by Blizzards dumbass choice to do a four year story arc without satisfying midpoints.
I think they vastly underestimated how sensitive their playerbase is. Nathanos was meant to be the first half antagonist, hence why he bullied the players, but people treated it like they were getting abused by the devs themselves.