Plus as others have mentioned, too low a success-rate for a small, moving, difficult to hit target.
Me? I'd rather them live so they can spend the rest of their lives regretting having been born, much less the stupidity of their actions that led to them being shot repeatedly in the pelvis after I dumped a magazine of 230gr. .45 HST's into them. The hips are a nice, easy target you can hit all day at short or long(er) ranges and guarantees incapacitation, with only a moderate chance of fatality but a very high chance of permanent injury, making it unlikely they will ever be a threat to anyone again - I suspect it's kind of hard to kidnap a child or credibly assault someone from a wheelchair.
My first thought at seeing this video was that he was very lucky I wasn't the parent there. I would have shot him. Perhaps the mother of the child will now consider carrying a gun?
Her fists worked good this time, but what about next time if the perp is armed? Y'all remember the young child grabbed from a buggy at a Walmart a while back and held at knife point? The perp was shot in the head and killed by a police officer when he began a countdown to cut the child's throat.
Crazy stuff happens all the time. You've got to be prepared.