At first, I was thinking why the hell would they not sell them to the army. as that would be a great marketing stunt.
however, it kinda does make sense. I mean, MS is known as this evil company; then the xbox is also know as this FPS, killing game machine, jocks and nerd gaming thing. So i can actually see why they would not want to ally themselve with the army or use them as a way to increase their console numbers.
in a marketing point of view, it's not a bad decision.