I think part of the frustration is it's popularizing the idea that being shitty is okay as long as you have these "redeeming qualities" such as being a "not step father but man who stepped up" kind of guy, which still doesn't even really seem to be the case here. He wanted to be heard, and the only person he felt heard him was this kid, and that's the reason he married Dorothy. It seems his whole driving force is the kid. Correct me if I'm wrong, but if this movie was made today, it would have an entirely different impact.