Jimmy, that's exactly my point. The masses don't have to get what an artist is doing in order for it to move music forward. Many genius artists are looked at as very popular at the beginning and middle of their careers and by the end they do something that upsets their fan base. But is the music really bad, or are they so far ahead of us that we aren't ready for the medium that they are working in? There is a whole book written on this which is very intriguing. I do not agree with the whole thing, but he poses it as a theory, which is not foolproof. It's called the Advanced Genius Theory
http://www.amazon.com/Advanced-Genius-Theory-Their-Minds/dp/1439102368
Now, musicians don't have to be geniuses to move music forward. But if what Ornette was doing was noise, then what was The Art of Noise? Or how much of free jazz has influenced noise rock such as the hugely popular Animal Collective?
Schoenberg pretty much came up with a 12 tone system which revolutionized the way we use western tonal music. It also opened the flood gates to chance music and Cage. Like I mentioned before, I can't stand a lot of later Cage, but he was definitely not writing stuff that insane and laughing on the inside. He was dead serious. You have to watch some of his videos and interviews. His heart was definitely in it.
Schoenberg's disciples were very committed to taking what he did to the next level, and Berg took the 12 tone system and made it rather lyrical. Several years later we are only beginning to appreciate some of these works. Even in the classical world, artists are shunned for years. Mahler was not played in America for almost 50 years after his death. His music has been ripped off thousands of times by film scores since then.
And I hate to open the can of worms, but without Schoenberg and Cage, we probably would not have minimalism unfold the way it did leading to wonderful music of Glass, Reich, and even the ambient music of Eno. No Stockhausen either.