I for one love violence in my entertainment media. Not all of it of course, but it has it's place. And when I do fancy playing a violent game, the more realistic, over the top, despicable, deplorable, depraved, stylised, or whatever wrapping the violence comes in, the better. I have never once been in a fight, nor have I ever had the urge or inclination to behave violently, or even confrontationally towards people in real life.
I just like having the option to play the part of a violent sociopathic killer if I so desire, and any study that says the violent media I've been regularly consuming since I was a kid has affected me in any negative way is wrong. I am confident that any study done in good faith will support this conclusion, but I'm worried it may be more politically motivated, and will come out saying whatever those that commissioned it want it to say.