weren't modern composition techniques pretty unpopular right away. It isn't like academic composers have been building off each other for decades with few listening and so now their music isn't intelligible. Rather the introduction of atonality, the 'liberation of dissonance' and moving off the diatonic scale were very rapid changes to music which were very alienating.

Pretty much. You have to be at least a bit of a mutant, or train to be one, to like that sort of thing. I think it's worth it, but I like it for its jarring qualities.

I think the key phrase here is: Your Mileage May Vary.

This prompted Adorno to say things like

The dissonances which horrify the public testify to their own condition and it is for this reason alone that they are unbearable for them.

I'm curious what you think of his position, actually.

That he was talking like an arrogant prat. But arrogance is hardly unknown amongst artists, and doesn't make his art bad.

Such clues as to the inside of the artist's head are often useful in reducing inferential distance - though, of course, what artists think they're doing and what they're actually doing can be widely disparate.