Your point is well taken. It does make me wonder though, if we imagine an scale of immersion into violence; from talking about irl genocide at the water cooler, to really getting into singing along with a heavy metal song about all the killing in war, to reading a violent spy book, to D n D, to watching violent movies, to playing today's most immersive and violent games (to playing them in 3D?); I do see that this scale has a top and that we're crawling toward utterly-convincing, but still not real, violent experiences. I hate video game legislation as much as the next guy, but frankly, I pause at the thought of tomorrow's kids who'll go to school with the kid with no parenting and easy access to purchase "Stabby McGee; Reign of the High School Shank-Master III" to go on an utterly-realistic random stabbing-spree, in a school, for four hours a night.
Of course the other half of me is screaming all of those concerns are idiotic, that his inability to handle a video game is, in fact, the parents fault and that by the time immersion like that is possible, it will be just like books and today's video games--easily separated from reality.