Prediction for the future: Microsoft will open source Windows but sell commercial support packages for it. Windows server will be offered as a compatibility layer in Linux on top of Docker.
Having said that, I can't do anything but blame it for the slow pace of computer systems research. My reasoning is that the OS does not sell anymore (partly due to FOSS movement) and thus research computing environments hardly come out of the labs for use in production.
We are forever stuck with Unix's interpretation of what an OS could be, and there is very little compulsion/motivation/incentive (can't think of the correct word) to explore. People who do explore (example at MS research or Later Bell labs, remains in the labs)