Prohibition 1: Liquor. Failed, created criminal sydicates.
Prohibition 2: "Drugs". Failed, etc.
Prohibition 3: "Piracy". Failed, made most people criminals.
Prohibition 4: Guns. But it can't happen, not even massive background checks can't work. There are far more guns than people in the country. How are we going to take them away from the people, now criminal, who own them? Background checks, house checks, trackers, whatever - a massive, guaranteed-to-fail undertaking which will manufacture a lot more criminals.
We can't keep trying to fix everything we don't like by making it illegal. It just won't work.
Guns are bad, yes, because they are designed to kill. Societies like ours like to use them to settle scores, here and abroad. But what possible scenario can one envision that makes them go away? Think! Cure worse than disease. And a lot of gun owners aren't going to cooperate.