Remember, he was talking about being dragged along to a concert. And many live Zep shows were out of tune and sloppy as he said. Page strung out, Plant singing off key. If that was his first or only exposure to them then his comments would make sense considering the discipline he came from. I don't think he liked avant garde or the drug addled bebopers either. Consider that he set the bar pretty high for musicianship, both for himself and anyone in his band. Some wasted guys playing out of tune and slopply over 12 bar blues progressions, or simple vamps (remember, Rich was coming from a pretty sophisticated musical place) wouldn't impress him much. Maybe if he'd been exposed to the tighter studio recordings, he might have a different opinion.Led zepplin don't know how to play?
Man he is such full of himself, I can puke.