You mean like the small guns, right? They are not being used not because society deems it morally unacceptable, but because the gun owners are afraid they will be counterattacked with guns.
I just had an argument about madness that is MAD: https://news.ycombinator.com/item?id=41776112
Actually, it would be interesting if someone researched the relationship between gun culture and acceptance of MAD. Both on national (cultural) and individual level.
People whose prediction skills are so bad as to use a gun without a good reason tend not to get in charge of nuclear weapons.
And yes guns are used as a deterrent a lot more than they are used to shoot to kill.
MAD is everything that held it all together during the Cuban missile crisis. Later countries agreed not to pursue ABM so as to keep the deterrent.
Your snark is misplaced.