These are people fighting people. Any guns would be evenly distributed among the defenders and the attackers, and thus not serve to end or cool the conflict, but further exacerbate the situation.This may be apples to oranges, but during the Los Angles riots that came about after the Rodney King verdict, while some rioters had guns they were way overwhelmed by the fire-power of people defending their property (mostly Koreans protecting their stores).
For whatever reasons some people view gun control they way others view drug control; that is, if something is available then oh-my-god everyone will have/use it. But it just doesn't play out like that.
For example, here in Arizona it is easy to get a gun. Many people have them, but I'd be surprised if they make up the majority, and we don't have routine daily gun fights here.
My anecdotal observations aren't going to explain any complex social dynamics, but some conjectures put forth in this discussion do not seem to be based in data or experience.
One thing that - to me, at least - has always been obvious is a direct proportional relation between guns and violence. Less guns, less violence; more guns more violence. Weapons are a catalyst for violence.
Switzerland.