Please do a little more research before you apply such a blanket assumption to a subject. Most criminals do not carry a weapon and the laws make this distinction - ex: 'robbery' vs 'armed robbery'. It is very seldom that someone who is committing a burglary is also armed. If someone brandishes a weapon, you let them have whatever it is they want, objects are easier to replace than your life.

I personally carry a 10mm (a VERY powerful handgun) on my hip and .40 caliber on my ankle, everyday, whether I'm at work or not. That should hint at the line of I've work I'm in. There have been 3 separate cases (in 3 different states) where I wasn't on duty that I can credit being armed with saving my life. I would consider that to be a very large crime prevention value in guns.