He wasn't the one calling ambient music generic unnoticed music.

Parent comment said generic, he offered these as counters, so he called them generic.

"I like ambient music"

"Elevator generic background music is trash. Good riddance. "

"No, X and Y in the genre are good bands"

"So you agree it is generic elevator music?"

I wouldn't summarize it that way, but I can buy the interpretation.

But how I read it, the second comment is saying that AI slop competes with machine-replicable human slop. Of which a lot of ambient music is, but not necessarily all.

Most ambient music boils down to generic muzak that was machine generated in the first place in a DAW.

Fair. Your characterization of AI music is a bit ambitious. AI still can't write a breathtaking short story or poem: it can write a mediocre one of standard themes indistinguishable from a student, but that's it. I would argue that AI images is a special case: a photograph is after all not truly "art".