Mr. Joe has a point. Some people just aren't interested in music. I know a guy like this, who does realise that mainstream music is watered down tripe but will still not delve very deep into any particular genre. I've given him Kreator, Testament, I've given him Emperor and Burzum and Skepticism and Forefather and At the Gates over the years, and he usually goes "WOW THIS IS REALLY AWESOME STUFF!" for a while, then a couple of weeks later he starts listening to hip hop or J-pop or some crud like that, or just doesn't listen to much music at all.
To him, and many (the majority of) others I suppose, music is just kind of an occasional diversion, in the same way I feel about movies, for instance: I don't really have any ambition to seek out obscure and admittedly artistically superior underground movies, because as a whole, I don't care about movies. When I do occasionally watch movies for diversion it's not like I'm unaware that it's mass-produced, shallow Hollywood tripe, I just don't care because to me it's occasional entertainment. That doesn't make me less intelligent, and for some people music is the same.