MS makes some great technology and some terrible tech... but the problem is the terrible tech gets the same blessing as the great tech. An open-source community is the best way to develop best practices and properly replace their false-steps.
So if people won't pay for operating systems what will they pay for? Stuff that still costs them money, i.e. hardware infrastructure and attendant maintenance and administration. Hello cloud. Development shops are happily sending Amazon millions of dollars a month so they don't have to buy servers, set up server rooms, hire system administrators, and worry about things like air conditioning, big UPS systems and emergency power generators, etc.
Alongside Amazon, Microsoft is doing pretty well with Azure. And you can run free operating systems on Azure, and .NET is already well supported on Azure. So what will sell more Azure? Make .NET run on the free operating systems. Now all the developers who like the free OSs on their personal dev systems are suddenly able to develop stuff they can deploy on Azure. What about all the devs that like Macs? No problem, make .NET run on Mac OS X as well.
I think this is all about making Azure services more compelling and more able to compete with Amazon than it is wanting to do "nice things" for the open source community.
In the end I think this is overwhelmingly a net positive for both MSFT and developers.
A lot of good things happening in Redmond right now.
Now if they can somehow fix this upcoming Lync is now Skype Business business, I'll be really impressed.
However, I think they know that if they completely abandoned the .NET framework, there would be a community of very upset devs that have spent their entire careers investing in Microsoft. Instead, they're doing a slow withdrawal and "giving it to the community".
I think that in the long term, they're going to be focusing more on Sharepoint, SQL Server, and Azure; less on .NET. That's just IMHO.
To be fair, he probably wouldn't have been able to set it up initially by himself. But I've had really good luck getting family members on Linux lately. I can Ssh in and do updates or make changes and it's way easier than remotely administering windows.
Also, being open source means being open and transparent about release cycles and roadmaps, which takes a lot of effort and initiative. I do think Microsoft can do that if they build a solid team of technical community evangelists, but otherwise, they will be swimming against the stream.