First, I was going to say the same thing Joe Erg said about how I roll my eyes whenever anyone starts defining what rock is and isn't.
Second, I think this article is similar to Nardwuar's argument - in his interview with Sean Lennon - that the Beatles ruined rock'n'roll music. Here's the excerpt:
Nardwuar: Because do you realize the Beatles ruined rock 'n' roll-
Lennon: What?!
Fan in Alley 1: No!
Narduwar: -because - Hold on! - in 1967, they put out the great album, Sergeant Peppers, and everybody tried to copy it and nobody could match it so all these fans - it was really bad.
Lennon: No, I know what you mean.
Narduwar: The Beastie Boys ruined the toque. They started wearing the toque, and everybody else is wearing the toque.
Lennon: I know what you mean.
Nardwuar: So, like, you are associated with two people who are-
Lennon: (speaking to fans in alley) What he is trying to say is that when somebody does something really great,everybody else tries to copy them badly, and therefore it ruins rock 'n' roll because, because, you know, all the bad imitations. That's what you're trying to say, right? Like Led Zeppelin or Van Halen - they were great but they inspired so many mediocre bands that all of a sudden they flooded the market with mediocrity and therefore indirectly, without knowing it, even though they intended to make good music, actually were ruining the scene by inspiring so many bad artists.
Nardwuar: Yes, exactly! ...