Or is the difference "murim" vs "real world" because in that same arc he says "they work the same" but will conduct himself completely different in them and it just works out because the author says so. If people can kill and cripple everyone around mc and he punches them and says to say sorry there is no story reason his entire family isn't killed. It would make more sense if that's the point but nah it's all good if he blatantly retaliates against an entire organization and let's all of them live because a single person said sorry they won't do it again.