John Dunbar, the guy who is kinda credited with introducing John to Yoko, said that if he had set out to destroy John Lennon he couldn't have though of a better way than to introduce him to Yoko Ono. And this guy loved Lennon and was a friend.
Do you have a source for this? I'd be interested to know. There is no doubt John loved Yoko and she was something of a spur for him creatively too. But I think artistically she was terrible for him. Here is a quote from an article and from John about his relationship:
"John regarded Yoko to a point of “just a little shy of hero-worship”. In an interview, three months before he was fatally shot, John said: “It is a teacher-pupil relationship. That’s what people don’t understand. I’m the pupil. I’m the famous one, the one who’s supposed to know everything, but she’s my teacher. She’s taught me everything I f******g know.”"
The article goes on to say:
"Artist Charlotte Moorman believes that “a hundred years from now, it’s Yoko Ono the world’s going to remember, and not with John Lennon or the Beatles.”"
Now, this is utter nonsense. Yoko has the profile she has because of John and there is something wrong with John's judgement if he came to think she was a greater artist. She was i think more of a thinker than John, but her thinking was strident and shrill like much of her work. We've been talking of George Martin whose arrangements were always deeply sensitive and driven by where the Beatles wanted to go. Yoko, even now I think doesn't have a clue what the Beatles were about and for the most part doesn't care.
The quotes I got were from this page:
https://journoyeo.wordpress.com/portfolio/the-story-of-yoko-ono/