Glee doesn't sit well with me either. I think Glee's success could be attributed to the fact that its cast is better than some of the pop acts that Disney is churning out. I'm not going to say that the cast is untalented or mediocre, because I think they're quite decent. Also, I'd like to believe that there's a desire for good music out there. However, given that most teens are exposed to some mediocre and untalented musicians, it's not surprising that Glee is rocking their socks off. And Glee plays the "we're outcasts like you" card pretty well, I would say.
I do think that if some of these kids decide to explore musical theater outside of "Wicked" (it's a good show, I just want kids to listen to a score with more substance, like say "Gypsy" or "My Fair Lady"), I do think the Glee cast will begin to look more mediocre to them. I don't even know how on earth I became interested in musicals (I'm in Texas), but it could happen for some of them, too.
I like your imperturbable perspicacity.