Hey man i never said that vito or Sonny were innocent of anything. They were both murderers. But even you gotta admit that they treated family better than Mike did. I mean Vito or Sonny would have never killed Fredo. they might have gave him a beating but they knew killing him went way too far. Also they might have agreed that Tom wasn't a wartime consigliere but they still valued his imput and treated him better than Mike did. i mean I think I'm being pretty honest when it comes to that.
Yes. As Vito states in the novel (paraphrase): there are some things that a man just can't bring himself to do. Maybe that's why I've turned things over to you. Vito could never murder his son? He could never even conceive of it.