While I personally prefer the PC over consoles, this is just wrong. In the future, there will probably be no single dominant platform. Each has it's own niche and users will flock to whichever meets their desires.
I don't game much any more, but when I do it is usually more in depth games that require a lot of time and effort to master (mostly strategy games). So that means that I primarily use the PC. However, I do play games on my phone when I'm away from home. And when I'm at home and don't have the time/patience to play a 'real' game, I play flash games in my web browser.
Other people will have different play style and use tablets or handhelds (eg DS, Vita), or consoles. Gaming as a whole is still growing. Companies shouldn't just ditch the current market leader at the first sign of a new one.
Of course once holodecks or neural interfaces become available, all bets are off. Once I have access to a holodeck I will probably spend all of my time either in the holodeck or making money to ensure that I can keep my holodeck.