Nobody has ever told me I was "blessed" with my parents, because when I describe my childhood people are usually shocked by what I say.
However, I've also done a lot of study into the subject (mostly because I wanted to figure out why I am the way I am) and I've found that mental illness can occur no matter what your parents are like. Yes, having a ton of stress can increase the chances of it, but it isn't a guarantee that it won't happen.
It doesn't sound like your parents were perfect, but rather that you may have been a bit neglected, since they didn't give you the structure you probably needed. You are right that you don't need to worship the ground they walk on, or necessarily be indebted to them either.
Anyhow, I appreciated reading this, because it also gave me something to think about, since it sounds like you're on the other side of the extreme from what I had growing up.