"The handgun is the only weapon that would give a lone female jogger a chance of prevailing against a gang of thugs intent on rape, a teacher a chance of protecting children at recess from a madman intent on massacring them, a family of tourists waiting at a mid-town subway station the means to protect themselves from a gang of teens armed with razors and knives."
I disagree. There are quite a number of other weapons, notably a submachinegun or automatic shotgun, that would work at least equally well in these circumstances.
Unfortunately, all other such weapons are a little impractical to haul around all the time. :)