I can't see killing a man, or even drawing a weapon because a person walks up to you.
Nobody suggested that. This person ignored a command to stop. Now you may be capable of knowing a mans intent simply by looking at them, most of us cannot. If you allow a man to get close enough to hit you, without attempting to ascertain his intent before he gets there and his intent is bad you are finished.
This isn't a city sidewalk where people have a reason to walk past you. This is the middle of nowhere. Someone purposely looking to make contact with you. You are alone. You are openly armed. Your only weakness at this point is allowing an unknown to get close enough to use his only visible weapons, his hands and feet. Not challenging them even politely is a huge mistake. Allowing them within arms reach is worst yet.
You trust and we verify. Two different philosophy's. Our way is undeniably safer.