"Hugh Mann?" Nice.
Anyway, the answer is pretty simple. Why do so many of us have more than one or two guitars? (I used to have 14.)
Why? Because it's what we're interested in and true collectors have FAR more. This isn't any different for those who have an interest in guns.
Actually, if having a lot of guns was really more lethal, then soldiers would find a way to carry a bunch instead of only a couple that they know how to use very well. Having 10's of thousands of rounds of ammo would be more of a red flag except, even there, I know people who love to spend lots of time on a gun range.
The bottom line is that you simply can't paint everyone with the same brush when it's always a VERY small minority that screw things up for everyone (take most of the traffic laws as examples).