This. I don't know what happened (that trend was already well underway before Ballmer stepped down) but lately they've been acting like kids suffering from ADHD

This. I don't know what happened (that trend was already well underway before Ballmer stepped down) but lately they've been acting like kids suffering from ADHD. Developers want stability. They had a good thing going with .NET which they could have simply used as the platform for making Windows Mobile apps as soon as the iPhone took off. Instead they chose to introduce a whole new platform (Windows Phone 7), then kill it off to make way for Windows RT (Windows Phone 8), then kill it off for Universal Apps (Windows 10 Mobile). You can't expect to build a good ecosystem when you establish a pattern like that.