Kidnapping for ransom is huge in, say, columbia where drugs are cheap. They hijack a bus, rape and take the rich ones for ransom. The rest are killed.
Let's say that you are willing to support the average addict through welfare. What about the cartel members, gang members and ex cons who want the cash that they now get by selling drugs? They aren't going to work at mickey ds or wally world for $8.
The answer to the thing you note is called the second ammendment. The first time four or five such types get on a bus and pull out their weapons, and then everybody else on the bus pulls out THEIR pistols and blow the gang away, 99% of such activity will cease, here, in Columbia, or anywhere else.