This thread is totally off the rails, but please inform me of all of the purposes you use a gun for every day outside of killing something or practicing to kill something. Again, I own and enjoy guns, target shooting can be fun.
It's not "drinking and driving" that serves a purpose, but driving serves a purpose. A car isn't designed for us to go crash it in to people. It gets people to places at speeds that we can not walk or run. Phoenix as a whole wouldn't exist without people having cars to get places. 95% of us couldn't even make it to the stadium without the assistance of a car, or two full days on horseback.
Wait, no, you said it only serves one person. You've already provided two. But, really, your original statement lumps a lot in all together.
One, of course, is that people murder other people with them. This is the least desired reason.
Two is that they are used to defend property, people, populations, nations, and the like
Three is that they are used to hunt, to provide food.
Four is that they are used to hunt, for sport (which I disdain).
Five is that they are used as sport, to show prowess or simply to enjoy.
Six is that many people collect them merely to have and never to fire.
That's six easy ones, off the top of my head. And if you want to start the "yeah, but most of those are to kill," I'll start parsing the uses of cars, for everything from smuggling to terrorism.
Bottom line, you know that was a silly thing to say. Own it, and all is well.