If I had a kid that young no I wouldn't buy ultra-violent games for him either.
I realize this stuff is in real life, but you have to realize that as a parent what you do has a different impact on your kid than what a stranger does. It's one thing to see it in real life than to see your parent is okay with it.
Kids see the sex and violence, but they also hear their parent's teachings. To see that a parent has no problem with those things tells them that it is not only real, but okay to do.
That is why parents are the ones who should be responsible when their kids are out of control......not the TV, movies, or video games themselves, but the parents that showed and/or told their kids it was okay.