Excuse my language, but give me a fucking break. I was a teenager not that long ago, my siblings are in their teens, and I know other teens who have zero interest in video games. Aside from the fact that I think the claim of impending ostracization for non-gamers is bullshit, if your friends shun you because you don't play 20 hours of video games a week, get some new friends. You could easily make the same arguments for drugs and promiscuous sex, which I understand are popular among some groups of teenagers. I'm sure there's a lot of people that would argue that it's a "huge social disadvantage" to not being into sports, but I've lived in many places were sports seemed to be all most people cared about and I managed to maintain plenty of rich friendships, despite not giving two shits about any professional sports.

Be who you want to be and who you should be, and if your "friends" give you grief, get some new ones.

EDIT: I'm not arguing that video games are negative either, just that this is the dumbest reason ever to let your kids do something.