I think Norman enjoys taking off on one of the Beatles or another-- they can't all be "good", so he picks one to pick on, and it will shift about over time. I guess Ringo drew the lucky straw this time!
People like Norman amaze me. They make their whole living sucking off someone else's fame. I believe part of him (them) is an honest fan; you couldn't spend so much time on a subject you hated. But then they get overly familiar and casual with their opinions, and start throwing them around as if they really mean something -- as if Ringo really did have no talent, and we'll just accept it because prominent scholar (yes, he studies) Phil Norman says so. It's kind of pathetic in a way. And I'm also envious, because if I could make my living sucking off the Beatles' fame like a bloated tick, it would sure beat my day job. So, kudos to Norman for drilling himself in to hold, but it doesn't make his opinion particularly valuable to me.
(All this was written without listening to the full clip-- it's my bedtime! G'nite!)