I can definitely say that for me, this is the straw that breaks the camel's back. I am turning my back on the .NET ecosystem, after having written C# for 7 years. The `dotnet watch` debacle from last year, still having key parts like the debugger closed-source and now again with this: It's just too much.
I do not want to build anything of value on top of such a shady platform that's completely controlled by one Megacorporation. It's too big of a risk.
No matter how many MVPs tout "MS <3 Open Source", how can anyone still believe them after these repeated violations?