Because it is not apple's idea, that's why. Apple's got a lot of good designs, exceptional user interface, and most people agree with their decisions. But let's face it, they're a bunch of control freaks. If they could lock down the mac like they did (mostly) with the iPhone/iPod app store, and they're wouldn't be a n outright rebellion, they would.
In this respect, Apple vs. Winboxes are like a really top notch cafeteria versus burger king. Great overall experience versus customizable but overall less quality food. Sigh..I need to quit drawing analogies before breakfast.
But I have to agree with you, that would be a cool design. Like the MBP's, if you didn't want the backlighting, you could turn it off.
Hey, I'm now a 68516! Whatever that means...