After having bands for the last 5 years, this year we have put an end to it.
Some of these reasons overlap what Larry mentioned, but I'll restate them anyhow.
1) They tie up parking. On Friday and Saturday when we push 2500+ through our house, we use every parking spot we have and still end up having people wait for a spot. Yes, it's a cool "scene" to have a band, but we're going to bring 2500+ in regardless, band or not.
2) It really screws with our cue line audio / actors.
3) The bands *usually* suck. Sorry, but they play for free for a reason. Don't get me wrong, we've had a (very) small handful of decent acts, but in general, they suck. Around here we get mostly younger kids who do thrash metal and slit-your-wrist-EMO shit that I personally can't stand. I love Pantera, but these bands suck. Definitely not a crowd pleaser for the most part. The folk band went over real well (/rolleyes).
4) One of our volunteers is a pro-sound guy and was awesome enough to keep his entire PA at the haunt for the season as well as come down and run it every night. It sounded great. Unfortuntely, he is more than likely leaving us to move back north and as such, no more PA. In years past, the bands were required to bring their own PA. We had to single out a lot of bands because of this, many don't have a PA or at least a PA large enough for the venue. The bands that were able to bring their own PA generally have no idea what sounds good or how to mix a live performance.
5) They don't bring any additional (paying) crowds. Yes, they might bring a groupie of 10, but none of them pay to go into the haunt, hell most of them expect to go in for free. We've always let the bands go in for free, which sometimes ended up as 20 groupies going with. We booked (and PAYED!) a fairly popular country act in our area. They were supposed to do all of the advertising for it, MySpace, website, etc. Seriously, a half dozen people showed up to watch them.
6) Stage - What are you going to use? We're "in" with the county and they let us use their stage, but it's an entire day project for 6 people by the time we make multiple trips to pick it all up and then assemble it to build the 24x16 stage. Then another 4-5 hours to tear it down and haul it all back at the end of the season.
7) Also as Larry said, it has nothing to do with a haunt. If people are bored in the cue line and we need to bring in a band to entertain them, that goes to show that we're not doing our job with cue line actors to entertain the crowd. We have a group of fire breathers / eaters that come in and do some really cool stuff. That also has nothing really to do with a haunt, but it's at least entertaining to everyone in the line.
Operations Manager & Technical Director