Imo his gray morality and his antihero status is what makes him such a compelling character and one of my top 10 favorite mcu characters. He doesn’t consider himself a hero but he definitely doesn’t behave like a full on villain and tbh he’s not a full on cold blooded murderer either. Cold blooded murderers don’t distinguish between those they kill but Frank has vowed never to take the life of someone who’s good and decent. I understand that his character’s not everyone’s cup of tea though.