But ideal is far from reality on
any subject I can think of.
OK, remove all guns from the equation. Robbers will still want to rob, for all the same reasons they do now. But now, instead of showing a gun and demanding your wallet, they have to get up close and personal. Close enough to threaten you with a knife, hammer, lead pipe.
That puts them at risk, so it would be much safer for them to just bash your head in, before you're aware you're being robbed. If you don't think being bashed in the head with a hammer/lead pipe is as bad as being shot....you're wrong.