Arguably, for those who want to / have to work in the .NET ecosystem, it is better that .NET is adopting an open source model, even if imperfect.

This actually lessens the vendor lock-in problem and also means less of a risk of Microsoft pulling out of providing security updates for key components.

So far as I can observe, C#, F# and .NET Core as a platform for web development have benefited from the OSS-ification in the form of more dynamic and transparent progress/evolution.

Disclaimer: I'm more of a Python/Django guy.

This doesn't make sense to me. My company (FireGiant) sells support contracts for the open source project for companies that want guaranteed incident response times/SLAs.

And Microsoft isn't involved. The .NET Foundation holds the copyright.

They "love open source" because that's what makes most business sense. FOSS is part of the developer zeitgeist so much that you can't avoid dealing with it. MS and others have bashed them for years, but it only got stronger. So it only makes sense to tone down the denial and start accepting that it won't go away.

Also they realized that there is a lot of free stuff that can be used for free.