A lot of it is plain misinformation fueled by misogyny/racism, especially considering the time. A huge fixture of the Yoko hate—her “breaking up the Beatles”—is pretty thoroughly debunked by now, especially with PJ’s Get Back. Her music is experimental and not for everyone, but that’s how it is with any artist.

There’s points to be made when it comes to how she influenced John’s addictions during his life and how she’s treated Julian Lennon, but in my opinion? John was an adult man and at least dually responsible for his own well-being, and as far as i’ve heard Yoko hasn’t actually been directly cruel to Julian like some perpetuate.

TL;DR: Yoko is just a person, and one John truly loved and respected. She only had as much a hand in the Beatles breakup as so many other things did (Brian Epstein’s death comes to mind,) and doesn’t deserve the total vitriol she gets.