Yesterday evening I have been reading the blog post "Why we terminated our partnership with Microsoft - Re: Next decade of open source" by Paul Stovell who founded Octopus Deploy.
Figure: Octopus Deploy homepage, https://octopus.com/, 2020-01-28 20:10
My first thought was that Paul Stovell has a valid argument here. Nevertheless, I continued to think about his situation. At the same time I also read comments at Hacker News about it where I originally found the blog post.
In the end I came to the conclusion that the specific situation of Octopus Deploy is not comparable to other OSS projects. Octopus Deploy is not an OSS project, only many parts of it are OSS.
Therefore it can be said that Octopus Deploy is a competitor of Microsoft. So you can't accuse Microsoft to have torpedoed an OSS project, but only to have made the decision to launch an own product as an alternative to a competitor.
Conclusion
As a conclusion I can only say that one should not be discouraged by this blog post to be an active contributor in a .NET OSS project or even start one yourself.
So I personally cannot agree with Paul Stovell's conclusion.
Which brings me back to Aaron's post: it's not going to work.
Yes, it can happen that Microsoft will eventually come to the point of offering an alternative and thus become the de facto standard, but that doesn't necessarily have to happen. This can be seen in enough popular OSS .NET libraries.
Basically, my observation is that Microsoft has made a fundamental turnaround in its attitude towards OSS since Satya Nadella became CEO. Maybe Microsoft had the idea to push OSS out of the market a long time ago. In the last few years, however, I have observed that this behavior can no longer be seen.