That’s true, but it’s a direct consequence of a legal climate in which guns are so loosely regulated and so prolific that an adequate supply readily sloshes over into the illegal market. Yes, we could buy a Glock in the “hood” quite easily. However, unless your “hood” happens to be tribal Pakistan, you can’t buy an RPG or a Stinger missile out of the back of a van. That’s not because the thugs have a different reverence for those laws, but because the legal distribution is so limited that black market spillover is low to negligible. Even putting out the word to buy such weapons almost always lands you a meeting not with a real arms dealer, but an ATF agent who will throw you away in the federal pen for decades.
So I don’t suggest that a tight regime would eliminate Glocks from the street, but it would mean that the price would go from, say, $500 to $5,000. There would be far fewer for sale at any given moment, the sorts of criminals with contacts and money to get them would be much more limited, and those crooks would, on average, be much more judicious about using them than schizophrenics or kids who drive down the street holding their “gat” sideways and spraying bullets on a crowded sidewalk because some other idiot “dissed” them.