General Discussion

PhD from an Ivy here (and I do philosophy of science for a living, actually)...avid gamer. I have zero doubt there are countless examples on either side of the gamer/non-gamer divide. Given the difficulty in performing an empirically rigorous reduction of confounding causal factors (of which there are a metric fuck-ton in a complex psychological matter like this), it's hard even to establish true correlation, to say nothing of asserting that gaming has any particular causal relationship to academic success at a high level.

I do, however, share your view of the effect of mindless entertainment in general. Or, to be more specific, the effect of overindulgence in mindless entertainment, which I suspect was your core point. The political implication lies in the area of the effect of a disconnected, broadly ignorant electorate on the proper function of democracy. Combined with the tremendous influence over political decisions that economic desperation possesses, and 24/7 fear-mongering in the media, we have in place a perfect formula for keeping the working masses pliable. I hate to sound like a tinfoil hat wearer, but I'm by no means convinced that's entirely coincidental.