Finding a new band to be a fan of is no longer as easy as just listening to the radio a lot, like it used to. You have to hunt sadly, but there are some amazing things being done with rock music right now. Currently, I'm obsessed with Devin Townsend's music. I also discovered this week a cool band called Unitopia, who remind me a lot of Peter Gabriel era Genesis.
I saw Devin Townsend singing for Vai back in '94. Fuck me that guy has pipes. Really amazing frontman.
To me the radio bands that are shifting decent numbers of records at the moment seem either to be a new breed of folk rockers, or bands still trading on the alt rock scene of the 90s. Popular rock music is pretty tame and bland at the moment. You are right though that if you are prepared to step away from that and go look, there's probably more great rock music around now than there ever has been. I mean, it's much easier to record and distribute now, and you can put together something decently produced on a fraction of the budget big releases used to get.