I was asked about porting a major live video application to the Surface recently. The Surface doesn't support flash in web views inside apps. It doesn't support HLS (without a third party library). They stubbornly insist that Silverlight and VC1 are still relevant. My answer to the request was, well, sure, but it will require a new encode farm, and rebuilding the app from the ground up. Which is basically a no-go.
Microsoft is very late to the party. Two other operating systems are there first, have far more users, and are generally more compatible with standards. Microsoft is late to the party, and clinging to all of their old proprietary baggage. And they wonder why they are losing.