Something stupid that people do in groups? Orgies. Yeah, they look good on paper, but in reality? Just a bad idea all around. Someone hogs the spotlight and gets all the attention, someone gets the short end of the stick (pardon the pun), someone gets something stuck where they don't want it, people get jealous, things get said, feelings get hurt ... it's not like in the movies at all.
All dancing is really stupid when you look at it. People wildly flailing there bodies around while music vibrates the room around them. That doesn't mean that it can't be fun. As has been said, fun is different to different people. The dances you mentioned are THE fun dances of certain people, just as the ones you mentioned. Not all humans are perfectly able to do wildly intricate dances, and thus, the YMCA exists. I'm not too smart a dancer, but I know all the ones you mentioned and enjoy them.
Seriously. Ppl who poke around in bits of other dead ppl need their own heads examined. By ppl who metaphorically poke around in the heads of ppl.
I know plenty of people who dance ******ed just because they find it hilarous. Terrible songs, play them more. Aqua - Barbie Girl, Hillary Duff - Any song of hers, Kelly Clarkson - Any of her songs too.... just to name a few. Some people just don't care what other people think and just do what they want. As long as everyone is having fun and no one is getting hurt, then who cares. Usually if people are like what the fuck, they are also laughing which is fine. I do agree with what you said about people going to the bar. Sometimes its just good to get out and have a relaxing drink with friends.