One quibble
On "Open Source .NET" you wrote -
> Chalk this one up to long-term strategizing from Microsoft's developer tools team.
which was a part of the Server and Tools division which in Ballmer's day was headed by, er, Satya Nadella....
Whether it was his idea we can't know and I find unlikely - the more likely suspect on this one is Scott Guthrie. But it would have been Nadella's call, just as it was Nadella's call on becoming CEO to, er, immediately promote Scott Guthrie.