I'm not sure any of us have figured it out. I grew up with the internet and video games. I was hopelessly addicted to Counterstrike for 15 years. I don't think kids should have complete (unsupervised) control over their own entertainment, but it's clear that strict limits aren't sufficient.
I think people have been looking at it from the wrong perspective and you hit the nail on the head. He was unprepared, yes, but... How exactly are we preparing our kids for the internet and video games? This is something we aren't talking or thinking about. Putting limits isn't enough. It's like forcing abstinence on kids without trying to teach them safe sex or about healthy relationships or character values.
I think there should be some limits, but there also needs to be an effort to cultivate interests/skills/experiences outside of gaming as well as a stronger focus on personal values/responsibility and philosophy in general.