Does anyone buy a new Mac and throw a fit when they can't get OS X 10.0 on it? No, that'd be idiotic.
The problem is, the current Mac OS X is far, far better than Mac OS X 10.0. And I would tell you that Vista is inferior, but I can't so much shake the mouse on my 2 year old laptop with 2GB of RAM without Vista going into swap spasms. It's a dog, even on new hardware.