Again, maybe I'm weird but I guess I'd rather get robbed or get my *** kicked than spend the rest of my life thinking about the time I killed a man and wondering if it was necessary.
I can understand why, even if I don't necessarily feel the same way. There's an adage that goes, "I'd rather be judged by 12 than carried by 6," and when it comes down to it that is the reason I choose to carry and accept that responsibility.
That being said, being robbed or even beat up I'd take over wondering about that decision IF I knew I wasn't going to die. My problem is, with an armed robbery as a specific example, I don't KNOW that giving them what they want will save me, they could decide to shoot/stab me anyway, it happens. The only time I would ever use deadly force is when I am in fear for my life (not just a black eye).
My view is likely jaded a bit by my career. For better or worse, I constantly see the darker side of humanity, and over time it makes you wary of people and what they are capable of.