IMO punk rock was in part a reaction to passionless arena rock dinosaurs like ELP and Yes. Oddly enough, both groups were extremely popular among stoners and acidheads. Passionless? Go listen to the entire version of ELP's "Pirates" and "Karn Evil 9"...then go listen to Yes classics like "Close to the Edge" and "Awaken" and then tell me it's passionless. Those bands were criticized for attempting to put TOO much emotion into their works.
At their prime, ELP and Yes were beyond great.