If games made us as violent as Thompson claims, he'd have had a .50 round between the eyes after the first five minutes.
Men are warriors, we fight to establish the hierarchy in the tribe, we fight to get meat, we fight to kill competitors. Men have always been fighting, men have always waged war. Games (video, board, sports) merely provide a way for men to do their fighting in a way that doesn't hurt others. Why do people cheat? Because it makes them the alpha in their particular scale. Why do people wear expensive clothes and buy expensive things? To rise in their personal scale. Why do people measure their dicks? To come out top and be the alpha male. The alpha gets all the women, the alpha gets to eat first, the alpha gets to rule. Alpha is power, alpha is survival of the genes, alpha is pprogression of the species. While the values of what makes you the alpha have diverged greatly and people have developed their own definitions of "power" in order to come out top on their own scale, the competition remains. Being proud of something means you consider it an important step to being alpha and those who don't have what you are proud of are inferior.
Declaring a console as "for kids" is a result of this, for example. To devalue a set of competitors you define their console as inferior and lower them on your scale so you still feel like you are the alpha.