Thanks for the explanation. I think I understand what you're saying.
All I can say is that in my former life in law enforcement, it seemed that everyone I ever apprehended for assault seemed to think they were exercising self-defense. For things like 'bad stares' and 'shooting off his mouth at me', and so on.
"Dude dissed me so I defended myself by cracking him the face." Yeah, no.
Typically, when we've discussed this notion here on MT, people tend to jump to the opposite conclusion and assume that the law requires a person to get punched before they can legally defend themselves, which is also incorrect. If someone says they're going to punch me, and they ball up their fist and raise it and they're coming towards me, I have every reason to think they're going to do what they are threatening to do. In legal terms, I've already been assaulted, and I am free to defend myself on that basis.
Now, reflecting back to 'moral' justification, everyone is different. And people are free to come up with their own definitions. As you said, depending on circumstances, they may have to deal with the legal repercussions of that.
"He had it coming" is not, despite popular theory, a legal defense.