Oh gosh, I'm really no expert! I only have my personal experience, which was a boyfriend who I walked away from over 20 years ago and who, it now turns out, is into his 3rd year of therapy in his 50s. Which, actually, I consider huge progress (for him). Easy to walk away from a boyfriend when you're young.
In my personal experience, people are this way because they were bullied or belittled or put upon or pressured unduly by a parent in their formative years. Avoidance is a coping strategy. Easier to pretend that stuff isn't happening. As a consequence, these people don't get to flex their conflict-resolution skills. They go through life just papering over cracks because the alternative is too difficult for them to handle, and it's too close to the bone. Too painful to admit your parents are shitty and you had a shitty childhood.
Assuming you're an adult, your father will likely be at least in his 60s. I don't want to say that beyond a given age people can't change. That's not true. But that's an awful lot of history to re-write, relationship histories to be re-written, realities to confront in a different light. Is it a kind, or realistic thing to ask someone to do that at this stage? Not sure.
And, if they can't or won't change, then your only solution is to accept it. Take them as you find them. Your dad doesn't want to see or know of or deal with the reality you lived through. You have to accept that. It makes him a lesser person, a lesser dad, and there's grief for you in that (on top of the grief of the mother you had). Accept it, and move on or away. I'm sorry for you. It's a terrible loss. Maybe just see the good in him and accept his limitations. We all have them, after all.
Finally, again only in my experience, people like this are well aware of their failings. Your father absolutely knows what went on and what is going on. He just can't handle it. It's about him, not you. The turmoil he must be feeling inside would be truly awful. Not easy for a parent to have to live with either. But this failing of you is less than the trauma of having to handle your mum's failings, for him. It would be immense, but maybe forgiving him for his faults (easier than your mother's faults, maybe) would be worth it if it means a closer bond with him.