According to an article on PC Gamer, Microsoft is planning to slowly and deliberately squeeze Steam off their platform.  With the introduction of UWP (Universal Windows Platform), Microsoft could just obsolete any software not bought from their own Store overnight.  Of course that would incite public outrage, so instead they will quietly release patches to make Steam flaky and unreliable, essentially pulling the rug out from under their competitor.  Users (in theory) would migrate to the more stable Microsoft Store.  http://www.pcgamer.com/tim-swe.....-windows-10-patches/

Sounds like a conspiracy theory doesn't it?  Sadly it wouldn't be the first time Microsoft has used this tactic.  https://en.wikipedia.org/wiki/AARD_code

Microsoft sees the success Steam has had, now they want users to buy from their store instead of Valve's.  As long as they control the OS, they don't have to make their product better to compete.  They just have to degrade the competition.  This is one of the reasons Valve released SteamOS, so they'll always have an open platform to run Steam on.  Here's how you can install SteamOS on your gaming PC: http://store.steampowered.com/steamos/buildyourown