I get your point, but come on, there have been a lot of 'actions' over the last couple of years. This only detracts from your argument. We've had .NET Core, visual studio code, the improvements on Git, WSL and more.
Edit: clarify my point.
Of course they are! Everything a corporation does is to further its own interests. Most (large) companies don't contribute to open source out of the goodness of their hearts.
This is a common misconception. It's a close cousin of the "increase shareholder value" school of thought, which has widely (and correctly) been called "the world's dumbest idea": https://www.google.com/search?q=the+world's+dumbest+idea
We exist in a complex society. It is everybody's job to maintain that society. We do that through things like voting and paying taxes. But also through making the world better directly. Companies that only do things they perceive to be in their immediate pecuniary interest are essentially parasitic. And, at least sometimes, are rightly shunned for their self-centered behavior.
If Microsoft is trying to grow up and be a good corporate citizen, I applaud them. But if they are, as you say, only putting on a mask of neighborliness because that's their plan of the moment to fill their pockets, then there's no reason to welcome or trust them.
The idea of trusting an entity that is designed to try to take your money seems silly and futile to me.
Companies don't act on their own or have beliefs. Only the people that make them up do. The company does need to turn enough profit to sustain itself, but beyond that, it's in large part up to the people who make it up. One of the thorniest problems in investing, for example, is the principle-agent problem, where people act in their own interests.
In America, that's mainly thought about as CEOs and executives serving themselves, not investors. But that's a cultural thing. In Gemany, companies are much more focused on all sorts of stakeholders. That's also often true in America with small and medium businesses, especially ones that are family owned.
Companies are hopefully designed to do whatever the stakeholders want them to do. Sometimes that's serving somebody's rapacious greed. Sometimes it isn't.
Microsoft has had a vested interest in Git and Open-Source for a while now.
If you need further proof, observe that Oracle is on the list. There's not a company on Earth more hostile to FLOSS than Oracle. And yet there they are, and a "platinum" member at that. Lol.
https://www.infoworld.com/article/3042699/open-source-tools/...