I have been involved and trained in Wado-Ryu Karate for over twenty years now, and have taken various other martial arts (for interests sake) over the same time. I consider myself quite proficient at hand-to-hand defence, no question.
However, even I concede that there are instances where a gun is superior for self defence. Personally, I'd rather take my chances without a gun no matter what, but that's simply a personal feeling based on my experience and confidence. However, it took me many years to gain that experience - whereas proper gun training can be significantly less.
If it was my wife or one of my daughters in a situation that required self defence, I'm not sure I wouldn't want them armed in some way - with significant proper training, of course. They only have a couple years of martial arts training, and I know that there is a great chance that they simply aren't physically capable of overpowering an attacker.
But, the one big positive of carrying a gun versus martial arts - the time it takes to be profient at it - is also a HUGE negative in my opinion. I know this is a sweeping generalization, but I believe guns tend to give their owner a false sense of security. With a gun at their side, they may decide to take that chance of "taking that shortcut through the park", or "walk through that group of punks hanging outside the store". Anyone trained by a good martial arts teacher for several years, has had it drilled into them to avoid situations like these.
As my old sensei used to tell us - "The best defence is to not be there when the shit goes down".
