That's why I carry another mag in the left pocket hehe
But seriously, it's not a shootout at the OK Corral, neutralize as effectively and quickly as possible and then move your a$$ and get as far away from the situation as possible.
I don't know how many shooting that you have been involved in, but out of my several, I've been involved in four where I took a total of seven rounds. The last one being 3, from a .38 Special(125 gr. HP). My point is, you never know how many you are going to need. The human body is an amazing thing and it's much tougher than many people give it credit.
I will admit that must people don't want to get shot by any gun, but I can also tell you that must of the time a person doesn't know right away that they have been hit even with a larger caliber. In the last shooting, the first two rounds were taken in my left shoulder. I didn't know that I was hit, the third round was center mass, left lung, near the heart and I was still able to respond. In other words, it didn't "stop" me.
I guess it all boils down to "carry what you feel good about," and for me it's a .45. I want the threat "stopped."