They get more money from selling 360s though.
Think about it. If you buy a PC and games for the PC, you only need that one device.
However, if the PC is a pain to run games on, you'll buy a PC for certain things and a 360 for others.
Then you have to get controllers, which run at 50 bucks a piece.
Add in the price of a Kinect, and they can make a lot more money buy selling you one thing, and then forcing you to buy another device for other things, rather than letting you do it all with one thing.
This is just capitalism at it's worst: people with money and power using that power to try and make the people dance however they like, all in the name of even more profit. A company is, legally, a person, and for several different reasons. Perhaps one is that, based on the structure of
how companies are run, you'll never see a company say "Ok we've earned enough money now. Now we're gonna cut people some sweet deals and be nice." No, companies ALWAYS try to improve and get more money. That's just how they work. If it weren't Microsoft doing this, another company would.
It's just a sad reality of the society we all live in.