I think there exist other problems behind bugs in games.
1) companies build up anticipation for a game was to soon, causing delays to turn away the fanboy and just making expectations to high and rush jobs. Seems to me lately the biggest non-franchise games to come out with huge satisfaction was less to no advertised games. Many of the RPGs of late except Blizzard ones get very little attention until right before release. August of last year rumors and such had already started for the Next SledgeHammer lead COD, Black Ops hadn't even been released yet.
2) PC configurations can't really be that widely different ATI and Nvidia both have unified Driver architecture, I have bought the cheapest motherboards and better motherboards and "compatibility" was never an issue, "Build quality of the product changed OVERALL experience not just one game or application. I find it hard to believe that PC gamers being such loyalist don't consist of a majority of certain brands and configurations (Asus, EVGA, XFX, Saphire, MSI, INTEL, AMD), Thus feel "very" buggy game is inexcusable, plus ever heard of demos release a demo earlier and let the gamer be a tester.
3) Lets be real, when talking about the COD series is re-hash tweaked graphics engine, overall, I played MW1/2 and black Ops and don't see much innovation in the graphics just tweaks...So at this point the COD re-runs should be perfected.