I'll far and away admit that a high percentage of guests that go to HHN and HOS (both of which i've worked at as an actor) drink heavily, but very few actually get to the point where they do this stuff. You have to think that HHN gets packed, so even a tiny percentage is a large amount of guests, which means that a small portion of a large audience are the ones harassing the performers.
You also have to remember the drunk guests are the loudest, so they stick out the most. When Uni let's the park fill up to capacity every damn night and they have a "scare zone" like Die-In, i'm not sure what they can expect. I'm not letting the offenders off the hook, but Uni needs to be the ones taking proactive steps as
@testtrack321 said earlier.
And unfortunately assault is nothing new at these events. I've seen scareactors get their teeth punched out and get physically beaten up day after day. Social media just allows people to speak out for a change.