I think some of this is just that anything done in their solo careers was continually measured against the best of the Beatles output. If you look at the number

I think some of this is just that anything done in their solo careers was continually measured against the best of the Beatles output. If you look at the number of hits and records sold by McCartney and Wings, it's amazing. And John Lennon's solo stuff is legendary. I still think that "Imagine" is as good as any of the Beatles stuff. And the Beatles had what I consider a lot of poor songs as well. It's just that their sheer volume of outstanding songs made it easy to ignore the lesser ones.