Common sense has little place in the business world.
It's a fairly well known fact that Microsoft was under a consent decree that prohibited such things and, while the consent decree is expired now, these practices are still in place. For example, how would you count a Windows license "gifted" from the WinDiv to the hardware guys building the Surface? The hardware guys are simply adding to the BOM the cost of the license and drive it down to the customer. Not doing that would raise allegations of dumping and potentially antitrust issues again (i.e. using a product - Windows - to drive sales of another product - Surface) just like Windows and IE years ago.