I believe the idea behind not including it is that you can choose the color of your keyboard without them having to anticipate demand for certain colors and package them together. I don't think that's a very good rationalization (just give them an option for keyboard color and ship a second box!), however.
I'm kind of dumbfounded by this. People like personalized goods, this is no different from picking a colored iPad case or wanting your car in some color other than Ford Black.
