You can't count the money MS makes from the OS as money made with games. MS sells you the OS one time and earns profit from it but you were probably gonna buy that OS anyway (if you buy a pre-build computer you are always buying a copy of windows with it), but every game that will come from X1 to PC and does not belong to Microsoft is not a profit they are making, is only an exclusive they are losing and all the profits from the PC version of that exclusive will go to the company that made the game.
Indirectly it adds to the system, Where else can you do that? So I can do exactly that. Your argument is flawed.