ELP isn't over requested, the other three bands are. Worse yet is that it tends to be the same handful of songs from these bands. There is a lot of GREAT progressive rock out there besides Yes, Genesis, and Pink Floyd, a lot of which is better than much of the afore-mentioned bands.
Progressive rock has always been about pushing the musical envelope; hearing "Close To The Edge" for the 7 millionth time doesn't qualify. At that point, it's no less boring than Britney Spears (except Britney only took one listen to be that boring.)
You're certainly entitled to your opinion, but you're missing out on a lot of great music with your mind so closed.