They want devs to write for Linux because they are a services company who make money from Azure VMs including those that run Linux.

They don't want end users to run Linux desktop.

So devtools/languages/cloud divisions inside Microsoft like Linux.

Those in ms who deal with end user applications (home users in this case, as ms push Lync to business) probably see little point in investing in development in Skype for Linux.

This. MS want .Net to run on all platforms. Give developers awesome tooling for free. Let them build. When they deploy, pay for Azure. It has an ongoing usage cost. Xamarin is just part of their tooling.

Skype on Windows Phone is horrible. Updates come to iOS and Android, and only then WP.

Microsoft is a very big company. Just because devtools division is doing one thing doesn't mean the Skype team has the same priorities. I wouldn't even assume that half the product teams in MS are using MS dev tools to build their product.

Exactly. It probably means that in 1-5 years, the C# experience on Linux is going to go way downhill. Extend embrace extinguish.

What are they going to extinguish, Linux? By letting people write C# code on Linux? Or are they going to extinguish Java? Or are you saying they'll extinguish Xamarin? If that's the case, that doesn't make since because Xamarin isn't a competitor.

Microsoft is so far from having the capability of doing any of those things. Any company that has a monopoly starts acting evil, but Microsoft is no longer close to having monopoly.