It's not as simple as most everyone having a gun which is the primary reason of low crime rates. It's the homogeneous nature of a society that is foremost to both keep crime low and national pride and tradition high. Switzerland is highly homogeneous; the United States is not.
I am a member of the IWLA and during a membership drive, one of the submitting new members was Swiss. It was very interesting to talk to him and he was right at home on the firing range.