Good point. By the way, have you read John Lott's More Guns, Less Crime? He argues that allowing people to carry concealed weapons reduces the crime rate, because criminals are less likely to attack someone if they think he has a gun. He shows through statistical regression that in high crime areas like urban ghettos, liberalized concealed carry laws reduce violent crime.
The criminals will always find a way to get a gun, even when guns are illegal, because criminals don't believe in obeying the law. But law-abiding citizens do, so if you pass a law banning gun ownership, it takes the guns out of the hands of the law-abiding while leaving them in the hands of the criminals. It's like unilateral disarmament. Guess what the result of that is? An increase in gun-related murders.
To be sure, as more people carry handguns, accidental gun deaths may be more likely. But it turns out that the number of murders prevented from allowing more people to carry handguns exceeds the number of accidental deaths.