Disposable Heart
Grandmaster
Though I'm one of those "years and years on the AR" guys I too recommend shotguns for home defense as opposed to carbine rifles for the reasons the OP listed. They're cheap, easy to use, reliable, and the main reason that nobody seems to have touched on yet is I want the biggest longest "club" I can have if I'm fighting someone. Length is detrimental in home defense situations unless fighting from a fixed position. The more length, the more leverage that can be used against you or that you have to contend with going around a corner
Fighting inside a house may not be Seal Team Delta Operator-esque like all those ECQCB classes point you toward. You may not need to clear the room with your buddies using your 580 lumen rail mounted cree bulb. Chances are there'll be a noise downstairs, your wife will bump you in the ribs, and you'll flip on the lightswitch as you walk down the steps with your shotgun in hand. In a case like that, you may find the methed out kid from down the street, your daughter's boyfriend, or maybe a couple of friendly burglars.
Are you going to dump 30 rounds in your living room? Absolutely. If two or three rounds will not perform the task, then dump the magazine
I find it funny that gun owners always assume it's going to be a deadly force encounter. Every single time he's going to have to shoot a squad of Rangers camped out in his kitchen. Why isn't the scenario a drunk teenager who's just looking for a place to ****? Because Indiana favors the concept of property rights in terms of defense. Someone breaks into my house, which has locked doors and secured windows, looking for a place to "****", then they have already become a threat in light of common sense and color of Indiana law. While every situation isn't one of deadly force, we have to be prepared as those who don't, do not win the day
In all these "less than platoon size encounters," would you rather fight someone (hand to hand) with an AR or a big ol' shotgun? I'm not doing that, the reason I have a gun is so I don't have to roll around with some jagov that broke into my house. By that reasoning, I would want a halberd or yari spear.
Having less lethal options should be considered in home defense. Personally, I have a 590A1 with the bayonet on it just for that purpose. The human psyche can be a weird thing. Those pointy sticks can sometimes be scarier than the black guns. Giving someone a "nudge" out of your house is pretty easy when you're poking them with a pointy stick. "But slim, you can poke them with the bayonet on your AR too." Sure, but it's going to be about a foot closer than the bayo on your shotgun. A bayonet is a lethal option, not less lethal. If I give someone a "nudge" with a bayonet out my door as they are leaving, I'm going to jail. Review Indiana state law on use of force for more details. I also eschew the concept of the threat of force as a valid deterrent, placing it akin to a sticker that says "I don't call 911" on my door. Does little to deter a determined or armed intruder.
Reach is important in a fight. Physics are important in a fight. While the AR is a great tool for running and gunning, I'd much rather buttstroke someone with my shotgun than the little collapsible stock on the AR. Again, if you want to close distance with an attacker that has already destroyed the sanctity of your home, go ahead, but I generally advise against it. Last thing you want is to be the person that is shot with your own gun.
See response in red...