By 'American rock' I was more referring to what might otherwise be called AOR or hard rock (rather than Petty et al): of which, like all genres, there is good, bad and indifferent. The BBC's attitude to that whole area has always reeked of class snobbery and, yes I'm going to say it, 'PC gone mad': as an example, and they've corrected it now, for several years the 'Radio 2 Rock Show' ran for 3-4 weeks per year, and one year was followed in the same slot by 12 weeks of a David Rodigan show focussing on reggae. And this was after R2 had declared it had become too progressive (ha!) and would instead concentrate on stuff that appealed to the broadest cross section of listeners. I have nothing at all against reggae/ska/dub, it's very enjoyable, but I must have missed the part of popular culture where it so comprehensively outsold hard rock music (if the ratio of rock programmes v reggae programmes mentioned above was reflective). But then, it was ever thus, R1 used to bury Tommy Vance's Friday Rock Show back in the 80s.
Sorry, it's a bugbear of mine, as you can probably guess.