It's true and GTA would fall under the same category. This would be a really tough task to accomplish for most modern or even recent games because there's an extended amount of dialogue.
I agree - some people aren't fit to be parents. It's the entire objective of the game - kill or get killed. What she should've taught him was that losing is a way of life and is the first step towards being the best at something.
Timing also has to be right because if the demand isn't there, you'll have to sell for a way lower price. Whereas at the height of the demand, you can get tens to hundreds of thousands of dollars for said game.
It's hard to say really because video games have a unique influence on every individual. One may become more tolerant, while another may experience the opposite effect and someone else isn't affected at all.