What I don't think you are getting is the "fear for your life" part. If you aren't in fear for your life, you shouldn't be shooting. If you are in fear for your life, you're not thinking "shoot to wound" you're thinking "I'VE GOT TO STOP THIS GUY RIGHT FREAKING NOW".
That's why you practice shooting center mass. Highest likelihood of ending the threat. You feel free to do whatever you feel comfortable with...try some psychology, or hot tea with lemon...when it's your family at risk. But after you shoot him in the ass and he pulls out his gun and shoots though the ceiling into your sleeping wife, or daughters, or sons bed...you come back and tell us how much better you feel that you "shot to wound".
You eliminate the threat to your life.
If they are still alive, but, incapacitated, and you go over and administer a "coup d' grace", most likely you will be charged with, and convicted of manslaughter or even murder.
No sane person wants to shoot anyone, but, no sane person breaks into homes, or assaults people on the streets.