My opinion is that the demonizing of video games was borne out of ultra-conservatism and ultra-conservatism seldom has roots in reality. They are people who have their emotional processes affronted and over react accordingly.
Video games can't make you a violent person any more than pornography can make someone comitt rape. These psychological flaws are already seeded and a demonstated propensity for violent games or pornography at most may only serve to make these flaws evident.
Combat veterans who are sometimes exposed to real violence for months at a time don't return home with the idea that's it's okay to kill people, they are able to make the distinction between the circumstances of peace time and war time.
I grew up with Zulus with whom it is customary to stick fight to prove bravery and settle disputes. Never did this suggest to any of us that it was okay to run around hitting people with sticks whenever we felt like it.
They tried to lay partial blame on video games for the Columbine massacre but psychologists have long since agreed that Eric Harris and Dylan Klebold would very likely have comitted atrocities in the absence of video games. Certainly people have done so without ever having picked up a control or watched a violent movie.
I believe ultra-conservatism has contributed and will contribute to more violence through propaganda and doctrine than any video game ever has or will.