Also getting to bigger picture. How do you get a large amount of people to pay for services? Look at Google(search, maps), Facebook, Whatsapp, LINE. Nobody pays for these things. Cultural we do not accept the idea of paying for a social network or messaging service. We view that as being lower than content. We do pay for content in the form of VOD services(HBO, Netflix, Amazon, iTunes, Comcast, Sky, etc...) or games(Sony, Microsoft, Nintendo, iOS games).
What if Microsoft's big plan is for xCloud to gain 200 million paying users across all the devices(XBox, PC, smartphones, tablets, set-top boxes) to mitigate the console-only problem they have with Sony & Nintendo? Also even bigger picture, Google is getting into game streaming and so will Amazon and possibly others(Apple, Facebook, Netflix). Microsoft already sees a gigantic game streaming market in 5-7 years that Sony isn't seeing.
Now imagine $20/month for xCloud. $20 x 200 million * 12= $48 billion revenue PER YEAR on top of everything they currently do(Office, Azure, Personal Computing). This is a massive deal to the Microsoft Board and why Nadella said 'gaming is important' to them.
So while Sony & Nintendo think the game is about selling the most boxes, Microsoft is thinking services, services, services and 'oh we'll sell a few boxes too'.
Bottom line - if you're losing the current paradigm, shift it.