While I think there is some truth in what he says in the article I also think it is a desire to hear enjoyable music - we had to endure grunge and then the boybands and whatever fad has come and gone. I think people enjoy listening to stuff they grew up on (pointing to the graying classic rock bands out there still) but the music itself is good. The new wave of glam and hair bands build on the success of their elders and they are gaining in popularity.