While thinking of a response to this, I think I realized it’s not the music itself, but the people playing it. For example, I was playing a round with my parents last year and there was a group of guys who were obnoxious by themselves, but were also playing music at obscene levels (props to their speakers I guess). But later we ended up playing through a group of mid 50’s guys who were also playing music, but at a respectable level (i.e. only they could hear it and they turned it off while we tee’d off).
So basically it’s a respect/decency thing more than anything. (and for the record, I never play with music. Prefer to be alone with my thoughts and nature on the course)