It all comes down to what you use your PC for.  For many of us, spending $500 a year on Vid card upgrades is not that big of a deal.  I have many friends who spend triple that a year on cheeseburgers.  It's a freaking hobby people, to each his own.
As far as the argument that 1-2 year old technology is "sufficient" to run games, well what the hell is the point of getting a snazzy new game if you have to run it at a lower resolution with half the effects turned off?
There are many games that will tax current high end systems.  I have a P4 at 2.13 gig, 512 megs of DDR, and a TI4400 and I still see MOHAA dip into the 30's on the extremely intensive stuff when running at 1280X1024 (the native rez of my LCD panel), Dungeon Siege will run around 30 fps with this fast setup at that same resolution... I'd hate to see how these games would run on a Geforce 2.