I bought my first (and only - so far...) AR a few days before Sandyhook. I don't "need" it, but fortunately "need" doesn't appear in the 2nd Amendment. I don't hunt with it, but fortunately that doesn't appear in the 2nd either. It is very good at making a political statement though.
Turns out all those other AR owners are right - the darn thing is a heck of a lot of fun to shoot. Relatively light and easy to handle with very modest recoil. It is even more fun with an optic on it. Sure, the bare-bones iron sights look has some old-school appeal. But the optics make it easy to shoot well.
One other thing an AR is good for is getting dirty. If Mr. Stoner missed an opportunity to create a nook or cranny where carbon and soot could accumulate...well, I don't know where that would be. Owning an AR will teach you, really teach you, how to become very good at cleaning firearms. I think I caught my Glock and Mossberg sending thank you cards to the AR... ;-)
Actually you will need your AR when the SHTF. You should buy a gas piston AR that doesn’t get as dirty as direct impingement. Also you will need at least 10,000 rounds of ammo for each AR.