I've heard this reasoning before, you assume that if one guy with a gun sees another guy with a gun they will each think the other is a bad guy.
Has it ever actually happened, that one bad guy caused multiple people to draw their weapons and then everyone shots each other to bits?
Very rarely do armed crimes and gun carrying citizens meet. Certainly not in large enough scale for this to occur (thus far). But it does demonstrate the flaw in the argument that "if everyone had a gun, the criminals couldn't get away with it".
Usually with shootings, their intent seems to be to simply kill people, not get away with it. Add in people in street clothes packing heat, whipping out their glocks, or whatever they have, and you've got chaos.
I don't know about you, but even if I have a gun, I have a strong disinclination to being around other people I don't know who also have guns. Especially if there's a shooting in progress. There might be multiple shooters, a single one, he might have associates in another location, and I can't be sure if the yahoo across the street is just some yahoo exercising his right to open carry, or a shooter.
If I had the choice, I'm gonna get the hell out of there. If I'm forced to stay, I'm finding a corner and assuming anyone approaching with a gun is hostile. Especially if my girlfriend is with me.
Add on top of that unarmed people even less likely to be thinking clearly, and they're going to be running from anyone with a gun. They're going to crowd exits even worse, some will no doubt blunder into the real danger trying to escape the overzealous Texan in the crowd.
Guns and an armed populace have their place and their purpose. Serving as their own law enforcement is not one of them.
