If I want to play the new Wolfenstein, or Watch Dogs, or any "new" game, chances are my 2 year old PC will not be able to run it well (unless I spent $$$$ on it, rather than $$). If I want to play a new game with all the dials turned up to 9 (or 11), I basically expect to spend $1200-$1500 on a new PC every two to four years.
If I look at OLDER games, it's even worse: Will this game even install? I have a giant library of games which I would love to play, but I can't figure out how to get them to run on a current version of Windows. (Sea Dogs, Starfleet Command 3, etc.) These games are ten years old, and I can't even get the installers to run correctly -- or if I do, the game crashes for other "win 8 >> Win XP" reasons. I would pay money _again_ to be able to play some of these games in a reliable way (and have re-bought things for Steam), but most of the time they're not supported anymore.
My Wii will still play Windwaker (11 years old), and I can buy an XBox and any copy of Halo and be pretty confident that it'll run, even if ten years old (assuming the hardware hasn't failed).