I think the Microsoft developer community was given plenty of opportunity to innovate on Microsoft's "superior" proprietary platforms but they didn't produce anything substantive. In the mean time all the interesting innovation has been happening on the open web and non-Microsoft mobile platforms.
Microsoft as a platform vendor depends on you to make apps that make their platform more attractive. But they can't wait forever for you to produce. They've waited years and gave you stuff like WPF and Silverlight and what have they gotten in return? You didn't give them any reason to keep catering for you.
So they look at the non-Microsoft developer community with a sort of envy. They are courting the developers that made Android, iOS and the Web successful instead of their "old guard" (.NET/Win32 developers, etc.) who haven't been very productive at all. They want developers from the Slashdot community. You know, the "trolls".. who maybe used to spell Microsoft with a dollar sign but these are more concerned about the rising power of Apple and Google.
Unfortunately since you bet on a proprietary platform your skills don't transfer, and if proprietary platform X you specialized on goes away, so goes your career along with it. You have no control over your own career, but thing is, you never had any control because of the choices you made and were probably warned about. So you are angry, I get it. All I can say is we told you so
Huh? Proprietary versus FOSS? How is that displayed in current market data? Apple is the largest by capital and is proprietary. Android makes more money for Microsoft, a proprietary company, than the originators. Google just flipped the open source community a fork on Webkit so they could, in my words, move along without the baggage, a decidedly proprietary approach. I'm not seeing it.