> Consider - it their main focus here had been EEE then BSD would have been a far better starting point. The GPL is far more restrictive than the BSD license.
What Microsoft has created is binary translation for Linux system calls, like Wine but allowing Linux to run on Windows instead. FreeBSD, among many other OSs, has done something similar for a long time, precisely because Linux is the most popular Unix-like OS. In addition, Microsoft doesn't care about the drivers -- everyone still writes drivers for Windows.
What Microsoft has created is binary translation for Linux system calls, like Wine but allowing Linux to run on Windows instead. FreeBSD, among many other OSs, has done something similar for a long time, precisely because Linux is the most popular Unix-like OS. In addition, Microsoft doesn't care about the drivers -- everyone still writes drivers for Windows.