Rock 'n' Roll:
https://www.youtube.com/watch?v=kpTpxbnBWYM
Classic Rock:
https://www.youtube.com/watch?v=Mln0RciE2o0
If this isn't a good enough explanation for you then you are simply a moron, or at least completely ignorant of music and have no grounds to say ANYTHING about music categorization. Like Frink said, just because the explanation doesn't satisfy you doesn't make it a valid explanation.