Microsoft Hoses 360 Users for Free DLC

In a remarkable change PC users don't get the shaft from their games proponent. Seems the upcoming DLC for Left 4 Dead and Team Fortress 2 will be purchase only for 360 users thanks to M$ and their "economy of value". I can only assume that means "keep them bleeding from the nose" in laymenese - after all they just dropped $100 off your next 360 replacement, what more do you want? A free HDMI cable?