Like a lot of people have already said, people are complicated and contradictory; they are rarely one thing.
So you can judge him for, and learn from, the way he has treated other people, while also being grateful for the love, respect, and good parenting he has shown you.
Another aspect is that people often make mistakes and grow from those experiences. It might help you resolve some of the dissonance to talk to him about those things. Many people have experienced that having kids radically changes their priorities. Some people are fiercely loyal to a few people, but couldn't care less about everyone else.
Yeah, you stupid vending machine, just accept it! What are you broken and incapable of accepting a perfectly good dollar!?
But forreal, as someone who relates to this meme and would love to not feel awkward when getting a compliment that I recognize is valid, this is kind of like telling someone with depression to just cheer up because it's all in their head.
Edit: on reflection, my reply was more aggressive than I intended. You're right of course that, just like that wrinkled bill, the compliment is valid. Accepting it though is something that requires a lot of practice and effort for many people.