I keep seeing this repeated over and over again, and it doesn't square with my experience. I was surprised at just how small a pattern my cylinder bore (no choke) 12 gauge produced with buckshot. For home defense we're talking very short distances and the shot just does not spread out that quickly. And even if it did, the pattern density would be low with only a few pellets producing wounds.
"Don't have to aim a shotgun" is wrong, and may get the wrong person killed. A home defense shotgun needs sights and the owner needs to practice using them.
Yes, of course one needs to practice, but in the middle of the night on short notice, a 12 gauge will do pretty well. When I was a kid, my neighbor’s daughter was babysitting when an intruder broke in the front door. She had never fired a weapon, but knew her dad kept a loaded 12 gauge in the bedroom. She grabbed it, pumped it, propped the butt against the door frame and fired in his general direction. The intruder fled and ended up in the nearest ER with a minor leg wound.