why would you sink 2x the cost of a console into a card that will be obsolete in a year or two?
As a matter of fact, GPU makers do manage to milk their product line over a long period. Any x70 of generations 6-10 still outperform recent generation x50 or x60, which themselves allow decent playable gameplay at a mid-range resolution (1080p/60? ).
So if you bought a 670 in 2011 for $700, you're NOT beating me with my $150, 3 year renewal policy for x50, but I'm only a casual gamer with other expensive hobbies and I'm satisfied with playing old AAA games on sale on Steam (Gaming was already good enough 10 years ago and 10 year old games are not obsolete).