...it seems that everybody and his brother still carries knives. Imagine.
As anyone who's watched the opening sequence of 2001: A Space Odyssey knows, it's tools that separate us from the lower animals, or as we call them, "food". The more advanced tools of self defense can put a none-too-athletic accountant on par with a charging lion, or make a slip of a girl level with a linebacker. Take away the advanced tools, and we're back to the waterhole in the Kubrick flick, where the biggest, strongest, or most numerous monkeys ruled.
That's what disarmers want to do to you; put you at the mercy of the bigger monkeys.