^Yeah, I think here we forget that that majority of the public who attend HHN aren't necessarily haunt enthusiasts, they're just looking for an excuse to have a a fun time/party. The huge success of the bar area emphasizes that.
And while I was also disappointed Jabbawockeez didn't really have anything to do with Halloween, they are good entertainment in general. Their show in Vegas have been running for well over 10 years, so clearly there's entertainment value there in the eye of the public. Add in the fact they're locally based, it makes for a good, if unlikely, fit.