onhwy61 is correct. It is the way they are recorded and produced (pot smoking punks). Usually to make up for poor musicianship and vocals and the media for which they are heard (JVC,Pioneer lofi electronics). I love RnR and have found the live recordings to be listenable and alot of Pop music. Bands like John Cougar, Sarah Macglaulin, Paula Cole, Madonna, Joni Mitchell, Burton Cummings etc are all produced and recorded well and very listenable. Its not that you can't listen to the music it just sounds like compressed mush. I was a huge Rush fan and was terrible dissappointed when I heard them on my system. But in my car, Rush still kicks. Trust me, a high end system will open the door for you to enjoy all music, just some more that others and for different reasons.
Rock and Roll Snobbery
Can anyone explain why otherwise high end, musical systems might "not be good for rock and roll?" Or why a system that sounds fine for pop and rock might not do justice to classical and jazz? It seems to me that a great system should sound good with all types of music and that a good for classical system might be deficient in bass which is not exactly state of the art.