Being of a different generation, I listen to my music loud. I enjoy it that way. Things that make my father cringe. :-)
I am one of those who sings along in the grocery store if I know the song. I also have the ability to block out much of what is going on around me; the behavior of my fellow shoppers irritates me much quicker than the music the store is playing. I find it interesting that noise (read music) you don't like is "racket" but noise you do enjoy is fine. Just because it's not my taste doesn't mean I should be able to speak for those who are enjoying it.