Most Helpful Guy
I used to think anything mainstream was stupid and so were people listening to/enjoying it.
This was when I was still a teenager (up to age 21 or so) and only really listened to any kind of Metal and Rock (including a lot of Alternative rock).
Now that I have broadened my horizon in terms of music and have 7 more years of experience, I don't particular think anything about people listening to mainstream/pop music.
Of course in terms of conversational topics I'll have more in common with people also interested in the music "genres" I like, but unless I'm talking with a musician or music enthusiast even that doesn't really makes a big difference. Besides, it's also interesting to get new names of bands/artists even if they're not really my preference by genre; I like giving things a try.
Taste is subjective, to each their own; as long as people are considerate with their music (i. e., not blast it at max volume in public places and whatnot) I don't see how their musical preference would actively affect my disposition towards them.
Most Helpful Girl
So I have a very eclectic taste but my friends are more from the "alternative group". I tend to think that some pop listeners are people that just care about their own social life and themselves. But alternative listeners think that pop listeners are stupid so they turn out to feel superior but at the end of the day they listen to mainstream stuff too.