I fully agree. It does seem silly that they have these cards, but they won't sell them after-the-fact.
But, sorry, you lost me here. Apple is a business. They don't OWE it to their customers to provide upgrades. Hewlett Packard doesn't offer after-the-fact video card upgrades. (Admittedly, the PC video card sector is full of them, but it's still not the PC manufacturer's job to sell them.) And the most certainly are under no moral obligation to lose money on the deal. (Yes, they sell memory. Do they lose money on it? No way.)
Apple does offer a PCI-Express
GeForce 6600, but that's sold mostly as a 'secondary' card, since it's the same basic card that is standard.
As has been pointed out, though, you can buy PC-flashed-to-Mac-compatibility cards through the right sources. And for less than Apple would likely offer it.
Please, though, leave out the personal attacks. People are trying to help, attacking them isn't helping your cause. (And mklos, you're just fueling the fire. Don't attack people just because they're a little angry.)
P.S. You would have gotten better responses if you had posted it as "does anyone know where to get a Mac-compatible PCI Express video card that's better than the default GeForce 6600?" Your original post was purely a rant/complaint, and not very inviting of constructive help.