AND THEN! Replace the synth with guitars, mandolins, banjos, and a little drum here and there. Then, replace Katy Perry with Marcus Mumford, and BOOM you have Mumford & Sons! And no one would notice!
This game is fun, let's play some more!
You're an idiot.
You're missing the point a little. I'm saying that Foo Fighters are successful for the exact same reason Katy Perry is successful; they both put out formulaic, easily digestible music. The only difference is that one uses guitars and the other uses synths. That's why I find the Katy Perry shot a bit ridiculous, since he praises Grohl for doing the same thing he chastises Perry for doing.