Heh heh, up where you are, EVERYTHING is south!
Anyway, you make some good points considering your particular environment and culture. I know almost squat about Norway (all blonde and blue-eyed, right?) but I suspect that you have a relatively homogenious ethnic population, almost universally shared culture, and a generous government dole provided by the state controlled export of natural resources. That type of scenario lends itself to a low crime rate since there is probably a pretty comfortable base standard of living, no major ethnic conflicts, and everyone just "gets along" since they have a pretty similar background.
Heck, I'd probably put up my guns and kick back with a few shots of iced vodka too if I was living in your slice of arctic paradise
But here in the States we have a lot of bad elements. A 6'2" (about 2 meters to you euros :P 225 pound (100 kilos?) thug doesn't NEED a gun to intimidate, injure, or kill a grandmother, young woman, or disabled man. 2-3 of those guys can even take on a robust isolated man.
But a gun is the great equalizer. No woman should ever be at the mercy of a rapist, no grandmother should ever have a drugged up guy kick in her door, and no father should ever fear for the safety of his children when walking down the street. Common sense and proper preparedness can stop a lot of things, but sometimes it just boils down to who is going to cowboy up and make a stand, taking their own wellbeing into their own hands.
Us Americans (and Brazilians too, apparently) have decided that it is better to accept the risks of an armed criminal population and go armed ourselves than it is to disarm. I can't help but look at the rising crime stats of England and Australia since they enacted strong gun control laws and be glad that I have a pistol at my side.