Many people play games on computers, true. I think pvarangot's contention is that most of them don't need high-ends graphics cards to do so.

I should have mentioned, that chart is for sales in 2011. Some of that is low graphics gaming, but people aren't spending $18.6 billion on bejeweled (maybe on Farmville though). If you take just the segment of the market that is "high-end graphics gaming" then it's still a multi-billion dollar a year industry. Why would a self-sustaining industry of that size just spontaneously go away?