Adding to this, speaking from at least 13 years of experience, every year there are new folks who discover in many ways the job of a Haunt Actor isn't easy. Sometimes it's due to a role and/or costume making it hard (e.g. Depth of Fear's Mouth-Brooders), other times it's due to unruly guests, the list goes on and on. And with the number of nights HHN runs, that is quite the gauntlet to undergo to the Nth degree, even for seasoned vets.
Yes, it can be a lot of fun, I wouldn't still be doing this if I didn't enjoy it. But there are folks who find out the hard way it's just not for them.