''I think it's like a cultural slur. When someone is from outside a culture, they'll say "all that music sounds alike," or "all those people from that culture LOOK alike," because they're not tuned in to all those subtleties. To a lot of people blues all sounds alike. I'm not tuned into the subtleties of reggae. I know there's a lot of it there, but it's just not my world. Or hip-hop. It's just all different for different people, and they should at least acknowledge that maybe they just don't know instead of criticizing. Maybe it's better just to back off and say "I don't know that."
-Poison Ivy Rorschach.
I like this point. I've noticed the same thing. People will say that all country music sounds the same, or all science fiction is the same, or all horror movies are the same- because they're not familiar with the genres. I'm trying to get better at saying 'I don't know that' whenever it applies.