Back when i was so young to be bothered by such issues, there was no such games to start with really, so it is pretty hard for me to get the whole deal... first GTA came out just barely before i hit 18 mark. Then again i also read Jaws book when i was 8.
Thing is i grew up in different environment, i read loads of books in my early days, i didn't have much problems with distinguishing reality from fiction, i also had the occasion to play games before they got violent. Damn, i was there when first arcade's with Pac-Man arrived in my country, i laughed when i played Prehistorik bashing big bad dinos with big clumsy club in their toes. For me it was just extension of fairy tales i read when i was 5.
Nowadays young gamers have access to all weird things from the start. Books are uninteresting niche you actually have to grow up to to be able to appreciate it. They don't have to go through the whole process of learning what video game is. They get shiny, close to realistic experience right away as soon as they are able to hold the pad in their hands.
It is parents fault, where too extreme example of gaming reality get to their children way too early. Plenty of safer games for them to start with. In my eyes, if a parent buys an M rated game to their child thats not even 11-12 years old without even bothering with what the game is about is plain ignorance and deserves a smack in the head, preferably with a thick wooden plank.