You also have to consider that LEO and military that use ARs in close quarters aren't alone. They train and act as a group. In the dead of night when someone may be in your home and you're going down a three foot wide hallway, by yourself, with a 90* turn coming up, having two feet of protrusion sticking out in front of you gives the bad guy a lot to grab on to. This is the point where he could take it away from you and kill you with it. Home defense isn't like war. In home defense, it's not a bad idea to have a free hand to defend yourself with or to avert an attack while you employ your fire arm. When something like that happens, it happens FAST. It's hard to throw your off hand up to back someone off when you have both hands holding on to a rifle. If you come across a guy that has 100lbs on you and he's too close to shoot with a rifle, you're probably gonna lose.