But do please understand that the people who changes their video card are not the majority of people, it's just the geeks who want the best performance to play the latest game. Most people really don't care about their hardware components and are scared about the inside, thus they wouldn't change the components themselves anyway.
I don't get that thing where when you want to be a "computer guy" you NEED to change things inside and modify stuff. I mean, most of us here are "car guys", how many of you did put a better engine in their cars? Changed the exhaust system, etc. That doesn't mean you can't enjoy driving it after a few years.
For me it's the same with computers, I couldn't care less about what video card I'm using, what processor I have, so long as it runs my OS and my programs at a decent speed (and I'm not talking just about Spider Solitaire and Word here), and most computers from these last years can do that. Quad-core, 8GB of RAM, etc. really are overkill for most people.