More often than not, it's not just our parents' influence that makes us who we are as adults. This is especially true for me. My parents are good, responsible people. I feel that I am a loving, caring person. But I didn't learn this from them, really. They taught me how to pay my bills on time, show up when I'm expected to, and be emotionally distant. It was my relationships with other people that taught me how to be loving.
So, just because a person turns out okay, doesn't mean that their parents are solely responsible for that. I love my parents deeply, but when I made my living will, I did not list them as guardians of my children in the event of my or their father's death. I picked people that I knew would raise my kids in a loving, affectionate, happy home. That's not to say that my parents would do a bad job raising my children, they just wouldn't do it the way I would. And I think that is the important factor.
Feelings may be hurt or judgements passed when selecting or re-selecting guardians for children, but ultimately all that matters is that we pick the people that will let us live on through our children and that will nurture and love them as close to the way that we would.