The only thing that would make Bill Gates very mad would be if NO ONE bought the X-Box. Exactly as you said, MS sells them at a loss to try to take over the game system scene. Why would helping prop up their sales numbers piss off Gates??? He doesn't care what the systems are used for, so long as he can claim he sold them! With friends helping like this, who needs enemies?
They sell at a loss but they make the money back on the software and if you dont buy xbox software he loses out its the same thing with printers its cheaper to buy a new one than buy new factory cartridges. :-)