@PortalSage
I get your point but I will not excuse a grown ass ADULT for his horrible behaviour no matter how he was raised. Him being raised horribly by his parents does NOT give him the excuse to continue the cycle. The same way that in your example Billy should not continue the cycle of bullying towards his little brother because he should know how much that hurts him, especially since he experienced that pain himself.
He is old enough to realize that that type of behaviour is not okay and doing the bare minimum does not suddenly make years upon years of neglect, which is a form of abuse, go away. He chose to run away and not acknowledge that his behaviour was bad. He even hid behind that prophecy and used it as an excuse as to why he was a terrible father.
Only now after she was done with putting up with his BS, not so coincidentally also when he can no longer control her, does he want to do something about it. That is just manipulative and toxic (as much as I hate to use the word). He is an abusive parent whether he likes it or not.
I'm not saying that the story is bad for having such a character. I'm just saying that I think it would be nice to see him left behind by himself the same way he has left her for years. Poetic justice and all that. Ofc I'm fine with it going the other way as well but I'm just personally tired of characters, especially female characters, having to forgive characters like him. It would be nice to see her just abandon him.
These are just my thoughts tho that are formed based on my personal experiences. You ofc don't have to feel the same way as I do. I'm just putting it out there as an opinion on the whole situation.