Radio has pretty much always sucked, IMHO. That is being said by someone who has never had much interest in mainstream rock; Stones, Beatles and Zep included. (Flame suit on) Sure, those bands are all talented and write amazing pop songs, but crap, I got tired of that stuff years ago. Same goes for new bands that are overplayed.
That being said, I remember KNAC out of Long Beach being pretty decent,
before they went metal in the 80's. KROQ also had some decent shows, most notably Rodney, late nights on the weekends. These days, it seems like the only radio stations willing to take a chance on different types of music are college stations or community supported stations.
If I want to hear decent rock and roll, I go to the local club and check out what's going on there, or, I go to band practice.
Right now I'm listening to sports talk. Not too exciting, but not offensive, either. And no Ashley Simpson.