They disarm potential victims. People who do not care about the law can always get guns in a country with 200 million guns and more coming in, both legally and illegally. That basic reality is not changed by politicians and media loudmouths who appeal to emotions and symbolism by crying out for more guns laws. You can always pass feel-good laws and ignore their actual consequences. In fact, we have already done too much of that on too many other issues.
Affluent homeowners pay to have private armed security patrols cruising their neighborhoods.
Many of them are also for gun control. Of course you don't have to have a gun yourself when you are paying other people to carry guns for you. We don't have to speculate. Studies at the University of Chicago show that violence drops immediately in communities that pass laws permitting law-abiding citizens to carry concealed weapons. Contrary to those to whom politics is an ego trip, both citizens and criminals have common sense.