Interesting point. I can tell you from experience that having training, or being exposed to someone shooting AT you is a big advantage when it comes to self defense. Too many people who have never been on that end of the gun freeze up. Deer in the headlights. I am still amazed when I see people training to shoot well for self defense will tell you they have never been shot at or on that end of the equation.
They are just as likely to be a running sandbag as the non-carrier.
But that is another thread.