I just stumbled upon this eye-opening post by a Methodist high school student entitled "Why I've Given Up on Youth Group." Here's a highlight:
I've always been frustrated with my youth group and youth groups in general. Am I completely knocking the youth group model of ministry? No. But, I do believe that it too often and too easily becomes a place to entertain. Youth group morphs into a social club disguised verbally as "fellowship time", exclusive cliques form, and God ceases to be the obvious focus. Once this happens, it's terribly difficult for the people deeply invested in the group to acknowledge.