There's nothing expensive about touch screens. They are nearly free to include in a bulk custom laptop panel design.
Go over to the Lenovo/Dell/HP website and you'll see that they offer a touch screen option for something like $50 and you can just choose whether you have it or not.
Go buy a $450 iPad from Apple and it has a touch screen. That's cheaper than any Mac on sale.
Hey, that's another great point, maybe Apple's laptops could be more customizable and modular, wouldn't that be nice?
You had me until the whining.