I think most developers would agree that "open source has won". I feel the aspect of it that you're focusing on here is the ability to choose the best-in-breed tools, and to be able to swap each one out individually as better options arrive. If Microsoft's approach with its open source tooling is to follow that mindset, I'm not concerned. If it isn't, then eventually people will either move on to other tooling or fork it.

Now, if we're saying that Microsoft should be spending more of their time on interop and portability but chooses not to prioritize their resources on that, then that just falls into the category of common complaints that people have with all open-source projects and what the contributors choose to spend their valuable developer hours on.