I agree that crap music isn't a new phenomenon. I like '80's music, but the '80's were crap. None of the other rock decades were immune, either, as you note.
I think the big difference in popular music now is that everything is so fractured. Way back when, people either listened to Q102 or WEBN. Their parents listened to WARM98. That was about it. Now there are so many stations catering to so many genres that it's tough to stay current with it all. And small labels, despite the proliferation of stations, still get short shrift.
Today it's possible to be completely unaware of a massively popular act like Brooks and Dunn or T.I. That would've been impossible a generation ago, when everything "popular" made its way onto one of two or three stations. In general I like the greater amount of variety out there, but everything seems so compartmentalized that if you don't force yourself to move around the dial from time to time, you'll never get exposed to things that might have forced their way into the mainstream back then.
I guess I'm saying that not only is much of the music "safe," but so are the stations themselves.