Why should the OS take up more operating power than it needs to? What does that achieve? OO yay! swirly stuff in 3D. The OS should be as invisible as possible, surely. If I could, Id be over to linux like that.
Its the same with, say, Itunes or Microsoft word. Take ages to load up, or do anything, have too many redundant options which just fight each other, and in the end, you can download winamp 2, which takes up 2MB, does everything instantly, folds into a nice innocuous corner, and doesn't try to jump in your face everytime you want to listen to some music.