Oooh, perhaps a trifle harsh? Speaking as a regular and very frequent gig-goer of some thirty years' experience, I've seen every kind of live attraction there is, and all the audiences they attract.
The first point to remember is that live music is all about enjoyment - and that's what the majority of people are doing, they're just having fun. OK, that enjoyment may leads to some over-excited bahviour, sometimes the result of a little too much indulgence of a "relaxant" of choice, but in my experience, it is rarely more than a little exhuberance you're seeing. A degree of shouting out, singing, and leaping about are all part of the release of energy that the excitement of a good live show can produce, and if that's not your idea of fun, you can always stay at the back or the sides of the venue, out of the way of the action!
If the audience really annoys you that much, you should consider enjoying your live music via concert broadcasts on TV, video, radio, or the net - they concentrate very much on the band and the music, and very little on the audience's antics.
What do other people think?