I really meant within the comedy profession in which the most scorned form is prop comedy, e.g. Gallagher, and one step up from that is music comedy, e.g. "Weird Al" Yankovic, who explained this ranking.
The ultra-serious and self-important presentation of much of the more spiky New Music is a big barrier to its wider appreciation.
The other day Shorty remarked...
Seriousness is an asset in classical music and the musicians who play it, and an obstacle in other genres.
I don't think the problem is to do with the spiky New Music being too serious, instead it's the institutions of European art music. They have been taking themselves too seriously and putting up barriers for a long time.
And of the examples you give I think only Cage was really taking himself much less seriously than the Europeans (and I'm not sure I got that right either).
I think Glass, Reich, and Bryars are just easier to listen to. Yes, Derek Bailey was an open and fun person and a miraculous musician so yes people wanted to and did play with him (he wanted to play with them too) but few people really listen to truly free improv like that. It's just too demanding. It insists on your full concentration, like an intense rapid conversation where you need to hear every word to follow along. Otoh something like gamelan can absorb your attention and be fascinating but it doesn't need to, you can drift out, think about something else, maybe go get a drink and chat with someone, and come back. It doesn't insist upon itself like free improv. So it is also with process/repetition composers like Glass, Reich etc, and indeed house/techno dance parties of the 80s/90s.
So agree there seriousness does present problems. I don't really agree that Philip Glass was much less serious than, say, Ligeti. Or that Arvo Pärt's popularity has much to do with humor.
Couple of historical foot notes. First, the Americans fetishize the European high art scene. A hundred years ago every American city had a symphony hall with functioning orchestra playing all the European classical and romantic golden oldies. I just gotta wonder:
Why? Good question. Second, I learned from
this wonderful Australian radio program that piano recitals were a much less serious affair before Glenn Gould's time. Theatricality, improvisation, and audience interaction were stamped out some time in 2nd half of 20th c.