That's a very simplified example. Obesity in the modern world, everywhere there is sufficient calories, is precisely such a mystery, clearly there is a calorie excess but what causes the overeating?Yeah, I know. It's a mystery, isn't it! It's kind of like my friend who can't for the life of her understand why her kid is gaining so much weight and becoming unhealthy. She says to me...
"I just don't understand it. I put the Twinkies on the high self but he still gets them. The cookies are in the cookie jar, out of sight, but he still goes through them faster than a speeding bullet. After I go to the store, it only takes him a few days to go through 3 bags of chips, 4 boxes of ding dongs, a jumbo bag of candy bars and every box of cocoa puffs in the house! And when I bake 2 dozen cupcakes on the weekend, he eats every single one! I don't know what to do!"
Clearly people get killed with guns (although occasionally with other things) but this probably also needs to be combined with a badly dysfunctional society to lead to the mass killings it does in the U.S.. But then things like chronic war-making would serve as condemnation enough of the culture even if there were no mass shootings. And then your back to: why are some societies so violent?
And I'm really not convinced there is any guarantee that people wouldn't get guns even if they were illegal (nor of course would I expect the law to be enforced equally, not if drug laws are any example). When I talked about different ways of approaching the issue though I can't say I'm strongly convinced of any video game theories as the cause, though it would be hard to argue graphic gore was *good* for people but saying it makes mass murders takes a little more than that.