Jeff Cooper is often called "the father of modern defensive pistolcraft" or something to that effect. He attemted to find some rationale for the sideways gun waza that is all the rage in the movies. He said some people believe a version of it was used by the Mosad when performing executions at point blank range.
I can see no reason for it, but it sure teaches the punks that would do such things bad gun handling and marksmanship. I consider that a great public service.
Another interesting fact: 90% of handgun shooting victims live, 80% of stabbing victims live. So it's safer to be shot than stabbed. I'm going to try to avoid both.