No, it's just that when the parents do find out what their kids are playing, they go and blame the game companies, when the game companies have ratings and put plainly on the front of the box that it contains violence....etc.
So I'm saying that if the parents have to buy the games, they will see that it contains violence, since it'll be right on the front of the box, and they will quit blaming the video game companies, because after all, they bought the game for their kid. Thus, the parents will be responsible if their kid goes out and blows away 6 kids in school and says he learned it from a video game. The parents are the ones who should be responsible for that...not the game companies.