I came across this well-written, reasoned piece explaining why someone would own an AR-15. The part that really hit me was this:

The AR-15 is less a model of rifle than it is an open-source, modular weapons platform that can be customized for a whole range of applications, from small pest control to taking out 500-pound feral hogs to urban combat. Everything about an individual AR-15 can be changed with aftermarket parts — the caliber of ammunition, recoil, range, weight, length, hold and grip, and on and on.

It’s less a gun and more a framework for a gun. That made a lot of sense to me. It’s a firearm that can be configured and used in a number of different ways.

So cops and civilians “need” an AR-15 because that one gun can be adapted to an infinite variety of sporting, hunting, and use-of-force scenarios by an amateur with a few simple tools. An AR-15 owner doesn’t have to buy and maintain a separate gun for each application, nor does she need a professional gunsmith to make modifications and customizations. In this respect, the AR-15 is basically a giant lego kit for grownups.

I still don’t agree with it. But I can see the reasoning behind owning them. Why I need an AR-15 is worth a read. Even if you don’t agree with the position. It explains why the weapon is so popular.