I agree with this. The reason those bands have had hits is because they have crossover pop appeal. Straight forward rock on the other hand hasn't really been selling well. The last huge rock record I can think of was Foo fighters and that was already a year and a half ago.
Yeah, I would say The Black Keys as well, but thats about it. When you are a "Rock" band your main audience is younger males who are more likely to steal the music they listen to. As opposed to pop bands who attract more women and skew younger and older (these are the people who still pay for music).
Edit: But I will say, I am kinda tired of bands complaining about a problem that is over 10 years old at this point.