It's purely about comparitive advantage and where they see the most ROI for each dollar spent.
Business software, cloud services, and sales of Windows are the easy wins that generate the best ROI.
The gaming industry is more fickle, more competitive. And while it gives the company a "cool" image and brings some consumers back to other MS consumer products and services -- gaming itself is not the catalyst for how well MS does in other markets.
I anticipate a spin-off Xbox gaming company to be born in the near future so MS can double down on the things that actually make them the most profit. They'll retain some ownership in such a company -- but I think it'll be through a partnership with a major entertainment or telecom company. Comcast is the company that springs to my mind every time this is brought up.
I predict NX launches in 2017 - not 2016
