I think that you're reading the tea-leaves all wrong. You also have made a few unproven claims.
Chief among them to my mind, is that Microsoft has made a "significant investments in JavaScript and node.js". Significant compared to what? Certainly not compared to .NET which has been a gargantuan decade+ investment.
In my opinion: A strong cross-platform C# eco-system is simply not good for Microsoft. They had to kill Silverlight. By backing Javascript, they bought some time. Silverlight was getting too good. Microsoft does not want a good, easy-to-use cross-platform kit with static-typing and native capabilities to exist. Anything cross-platform from Microsoft is a head-fake, a bare-bones concession, or someone's pet-project that grows into a monster which will have to be killed.
Significant, in the fact that there's now a less clear choice of what to use when developing a Windows 8 UI or server application.
>> In my opinion: A strong cross-platform C# eco-system is simply not good for Microsoft.
In that case it's a conflict of interests, as it may not be good for Microsoft, but it's certainly good for the .NET community which lets .NET developers re-use and leverage their work on multiple platforms. Fortunately we have Xamarin filling this void, but if it wasn't for them .NET developers would be missing out on the most exciting mobile platforms to date: iOS / Android.
Chief among them to my mind, is that Microsoft has made a "significant investments in JavaScript and node.js". Significant compared to what? Certainly not compared to .NET which has been a gargantuan decade+ investment.
In my opinion: A strong cross-platform C# eco-system is simply not good for Microsoft. They had to kill Silverlight. By backing Javascript, they bought some time. Silverlight was getting too good. Microsoft does not want a good, easy-to-use cross-platform kit with static-typing and native capabilities to exist. Anything cross-platform from Microsoft is a head-fake, a bare-bones concession, or someone's pet-project that grows into a monster which will have to be killed.
I could be wrong, but I don't think that I am.