I used to be an MS developer many years ago. I will say one positive thing -- MS makes a lot of very useful development tools.
However, I'm amazed that people think it's not MS anymore. They have not gained my confidence in any way in terms of this supposed altruism or whatever.
Linux in some ways has been one of very few possible Windows competitors on the desktop. The fact they they essentially decided to just swallow Linux into Windows does not make me think they are more friendly to Linux.
They will set it up so that it will _seem_ like your are developing for Linux, but due to some extensions or technicality it will only work on _Linux inside of Windows_.
So from my perspective it is amazing that people think this is a good thing for Linux.
And desktop apps developed for WSL will simply never be Linux-compatible out of the box at this rate, given that WSL does not contain any graphical or UI functions; MSFT has been pretty clear about this right from the start, and so I really can't see a scenario where people mistakenly believe just developing user-facing applications for WSL will make them "just work" on Linux, given that all the UI code is on the Windows side.