The tagline should be: If you take the professor’s side, you’re wrong. And an awful person.
The amount of privilege; male, class, and in this case white (the student, Carol, was played by a WOC in our school’s production), not to mention a severe victim-blaming attitude, that it would take to sympathize with the professor in any regard is staggering. If someone’s committing institutionalized, oppressive violence, then yeah, their feelings are not the ones worth giving a toss about, no matter what excuses, sob stories, or “but I feel…"s they offer up. It’s the victim’s.
So yeah, if you hate Carol, or think that she shouldn’t have taken the measures against the professor that she did, or deride her for being “social justice-y”, then yeah. You’re terrible. And I’d say that you’re missing the entire point of the play, but considering the tagline that it has, I get the feeling that it somehow missed its own point too, somewhere along the way.