Yeah, I was talking about this with my hubby. We came to the conclusion that, by carrying a weapon, their perception of the world as a dark and frightening place, and of their fellow human beings as potential threats is reinforced. I think about every time I reach into my purse to feel around for my keys, everything I feel in there brings various ideas to mind. Dry hands or lips, headaches, runny noses, etc. Just imagining carrying around something like pepper spray kind of put me off. Do I want to think about being attacked every time I reach for a Kleenex? Even briefly, idly or subconsciously?
By carrying a weapon, you're reinforcing a perception of the world that it's a violent and dangerous place, which is kind of an unpleasant way to live. You have to work pretty hard to justify that, which is why proponents are so black and white about the whole thing, and seem to live in a "two choices: kill or die" paradigm.
That's just our theory. Very speculative, but it makes sense to us.