I'd rather think Ringo was a Beatle because he was the one that fit.
I hate to say it but unless you're a musician you might understand it, but you've never felt it. The click is a magical feeling. From all accounts I've read, the lights went on the first time they played with Ringo.
As for whether he is good or not, I have a friend who I think said it best. When they get to that level, they're all good, in their own way. You can't suck and be in a professional band for very long.