In many ways, negativity stands out more than positivity. People mistook John's willingness to be negative for honesty. Everyone knows How Do You Sleep? was an attack on Paul, but much fewer people recognize I Know (I Know) as an apology, despite such unsubtle lines as "I know it's getting better all the time / as we share in each other's minds". In the very interviews where John insulted, mocked, and dismissed Paul he also made many positive comments, but those aren't remembered as well. The negativity is unusual, so it is given more weight than the positive.
So in this post I am going to cherry-pick the positive comments from two of John's more hostile interviews: 1970's Lennon Remembers and John's 1980 Playboy interview.
John on his guitar solo in Get Back: When Paul was feeling kindly, he would give me a solo! - 1970
On Apple: Paul had a nice idea about opening up white houses, where we would sell white china, and things like that, everything white, because you can never get anything white, you know, which was pretty groovy, and it didn’t end up with that - 1970
LENNON: Paul is a bit more stable than George and I.
WENNER: And straight?
LENNON: I don’t know about straight. Stable
“I Am the Walrus” was originally the B side of “Hello Goodbye”! I was still in my love cloud with Yoko and I thought, well, I’ll just say something nice to Paul: “It’s all right, you did a good job over these few years, holding us together.” He was trying to organize the group, and organize the music, and be an individual and all that, so I wanted to thank him. I said “the Walrus is Paul” for that reason. - 1970
I think he’s capable of great work and I think he will do it. - 1970
On Sgt. Pepper's Lonely Hearts Club Band: Well, it was a peak. Paul and I were definitely working together, especially on “A Day In The Life” that was a real... The way we wrote a lot of the time: you’d write the good bit, the part that was easy, like “I read the news today” or whatever it was, then when you got stuck or whenever it got hard, instead of carrying on, you just drop it; then we would meet each other, and I would sing half, and he would be inspired to write the next bit and vice versa. He was a bit shy about it because I think he thought it’s already a good song. Sometimes we wouldn’t let each other interfere with a song either, because you tend to be a bit lax with someone else’s stuff, you experiment a bit. So we were doing it in his room with the piano. He said “Should we do this?” “Yeah, let’s do that.” - 1970
I heard one track - the hit, "Coming Up," which I thought was a good piece of work - 1980
I kind of admire the way Paul started back from scratch, forming a new band and playing in small dance halls - 1980
I always had an easier time with lyrics, although Paul is quite a capable lyricist - who doesn't think he is, therefore he doesn't try. - 1980
"Hey Jude" is a damn good set of lyrics and I made no contribution to that. - 1980
The depth of the Beatles' songwriting, or of John and Paul's contribution to the Beatles, in the late Sixties was more pronounced; it had a more mature, more intellectual - whatever you want to call it - approach. We were different. We were older. We knew each other on all kinds of levels that we didn't when we were teenagers. The early stuff - the "Hard Day's Night period, I call it - was the sexual equivalent of the beginning hysteria of a relationship. And the "Sgt. Pepper - Abbey Road" period was the mature part of the relationship. And maybe, had we gone on together, maybe something interesting would have come of it. It wouldn't have been the same. But maybe it was a marriage that had to end. Some marriages don't get through the phase. It's hard to speculate about what would have been. - 1980
Paul was one of the more innovative bass players that ever played bass, and half the stuff that's going on now is directly ripped off from his Beatles period. - 1980
"Hey Jude" is Paul's. It's one of his masterpieces. - 1980