I think there's something sick about a huge audience just standing around watching a very few people. It ties into the sickness of a society where art is mass produced/reproduced.
The end result is 'artists' whom are motivated by the shallow desire to be famous.
And really, that probably covers just about all artists who are indeed famous. As probably no one else would want to put up with that shit. Well to an extent...
And then furthermore you've the people who want to perform live in front of a huge audience because essentially, they're power tripping. They love to be the center of attention, etc.
What it all is, is very anti-egalitarian. And not the sort of thing any true leftist would want to be a part of.
For that matter, anyone with talent who goes about trying to become famous must think we're living in something that still resembles a meritocracy. Which is to say a person perhaps that's young and naive at best. If not someone who believes that our society is basically working just fine. In other words: a conservative.
OTOH I can see playing in front of a maximum of a few hundred people. I've enjoyed such concerts. I agree with Roger Waters on this and can sympathize with him spitting on an audience member at one of those massive shows they used to put on.