Oh I so agree with you on this one. My first XH (yep, current XH is #2), and I have been divorced for almost 10 years. There is no way in hell I would ever think of letting him back in my life. Granted, he was an awful person and the only really good thing he ever did in his life was help create D11. We don't have a relationship at all. He decided to run when D11 was 1 1/2. We haven't heard or seen him in about 9 years. I can honestly say that life is better for both me and D11 because of it.
So maybe I can't really agree with you here. My experiance with XH1 is different because he's not around. But I know that when he was I didn't look to every interaction with him as did he want to come back or not. When we were done, we were done for good.