Why would you be surprised? This is just an ordinary "company pulls the plug on proprietary thing that they think isn't worth it". If you want to rely on a something, do not use something where some entity can pull the plug for everyone arbitrarily. There's no gain for Microsoft from people using this, neither for playing games nor for developers. It's not like they run an Android app store where they can get revenue or anything. At most this is a marketing blip for drawing people to Windows where they can molest them with ads, but this feature is not in any tech news anymore, so why put anymore work in it?