Is Fandom of Pop Culture a sign of Mediocrity?

I wonder if being extremely obsessed for something or someone related to pop culture is normal or implies some kind of intellectual limitation. There are several kinds of fans. Science Fiction enthusiasts are the among the most famous, being an element of culture themselves. But why limit yourself to a world of fantasy when the real science is so exciting and relevant to society as a whole?

Another popular case are music fanatics. Generally they pick a band, a singer or even a musical genre, and that becomes the most important aspect of their lives. It is OK to enjoy music, but isn’t there a limit? Is OK for adults, long beyond their adolescence, still have as a role model a rock’n’roll star?

I think that in the end you should broaden your taste and knowledge as much you. All things must pass, and limiting yourself to a single artist is a waste of time.