Both those countries require everyone to experience military service, where such a gun is used as a tool to kill. There's much less of a "gun culture" in those countries because guns aren't cool, everyone has used one, everyone is familiar, everyone understands what they are for, namely protection of the country as a whole.

If the alternative to making guns much harder to access is to conscript everyone in the country for a few years to try and beat the gun culture out of them, good freakin luck