I bought my first "M" rated game when I was 11. Ratings don't stop kids from playing games, it's the parents. Though I do want it to be more mature than kiddish so I'd be happy with an "M"
It's not the actual kids that are the problem, it's the advlts who think it's fun to act like complete idiots in game and then go on forums complaining about how kids are ruining the game.