I dunno about you, but I've never seen a criminal fly through the air like a clay or duck (actually I did once, but thats because he ran into traffic and got hit by a car). I am well aware of how one uses a shotgun for clay shooting and hunting, but that is a completely different task than home defense. Plus, I bet there is a massive number of people who have a shotgun for home defense who do not partake in clay sports nor hunt, and thus do not have the knowledge base/skillset to point the gun as you suggest.
And considering the OP was specifically talking about using slugs at longer distances, I think it is perfectly relevant. You're not gonna just point your shotgun to shoot groups at 50yds with slugs, the vast majority of people are gonna try and aim down the bead/rib/whatever it has.
If you can hit a clay disc that is less than 4-1/2" in diameter doing more than 45mph, a human body stationary or even running is no challenge at all.


















































