He's nto defending "them" as much as he's defending his stance to have them on the tour.
What does he have to "explain"?
If you don't like the tour...don't go. If you don't like certain bands, then don't watch them. It's a pretty elementary concept.
You guys make it seem like he's the one who discovered them, signed them, put them in the studio, produced them, budgeted their media buy, shot their video, etc... his job is to find popular buzz bands and bring them to kids who want to see them, and that's what he's doing. Blame the people BEHIND these artists (and society, for that matter).