It's in fact a very old discussion. I have owned (and played on) PCs since the 8086, CGA, no HDD era. and that issue has been discussed at lenght since the appearance of graphic accelerators... I remember that the first time I changed my rig to play a specific game was when I upgraded my second PC from a 80826 to a 80386DX with a Viper graphic card. The games in question were Red Baron and Aces over the Pacific...
As a matter of fact, I feel that the market is much more stable than it once was. A 5 years old PC, core 2 duo E6600, Geforce 7950 still plays a huge lot of things correctly. A brand new config takes 3 years or before you really start to get a real feeling of obsolescence. At a point it was down to 1 year or so. And the nature of the evolution is not a "graphical" or "gameplay' revolution like it one was ( like the introduction of ultima underworld, or the first true 3d flight sims were ) , but graphical candy.
On the other hand, the issue remains true and is indeed mainly linked to some form of disregard for the user base. Or is it just that optimzation costs time and money, so why bother ? they don"t want us to play their games for long, they want us to buy them.
Eventually, no, massive hardware requirement don't make great games. They could as well be boring, repetitive and flawed, or true innovative gems. There is in my view no correlation. I'm currently playing with Commander : Conquest of the Americas, Hegemony : Philip of Macedon and... TIE fighter win95 ( on a core i5 / win 7 laptop) . The latter is probably the greatest of the 3 ;-)