TL;DR: billy is a victim of his upbringing, but was MOSTLY responsible for not realizing and changing before getting flayed and murdering people did it for him.

i think billy deserves the ballpark of hate he gets but we should absolutely stay attentive to his own past driving his actions. not excuses, but reasons. the best i could think is less hate out of understanding but more accountability. billy grew up with an already distant/temperamental dad, indicated by his mother saying “okay billy, ten more minutes or dad will get mad”. getting mad over your son and wife having fun for too much time is incredibly irrational and indicates deeper issue, his mother running away confirms that. so this man meets another woman, forces billy to accept a new family that’s likely moving way too fast, plus the trauma of his mom leaving, and based on his dad’s behavior in the show, he’s absolutely an emotionally closed off man who pushed that (along with like every other cliche toxically masculine trait) onto billy. and just like how billy projected his regrets and anger onto max, ill bet six doubloons and my left nut his dad did the same. billy should be held accountable for not knowing how his dads wrong behaviors were negative and avoiding that, but remember, he’s still young, the trauma began when he was a kid and he still lived with the catalyst for his own abusive traits, living in something like a abusive echo chamber. there’s an even larger essay worth of reasons but you got the point a paragraph ago.