I may be wrong, but I don't think Canonical has the engineering resources to pull it off. Even if they did, the main issue is that Microsoft does not publish their API spec which is why Wine and ReactOS devs bend over backwards to be compatible with Windows binaries. It also does not make sense from a business perspective. Considering there is no demand for such a system outside of the very, very small number of hobbyists who run Windows games and software on Wine.

If these issues are anything to go by, there most certainly is a demand:

* https://github.com/Microsoft/BashOnWindows/issues/1494

* https://github.com/Microsoft/BashOnWindows/issues/1243

* https://github.com/Microsoft/BashOnWindows/issues/1516

Did you not realize what vinnes meant by "Ubuntu Subsystem for Windows"?

Also I want to add, if you want to use Windows programs using VirtualBox or VMWare (+ lots of RAM) is probably the way to go. The Windows stuff doesn't work on macOS either. (I even bought the CrossOver stuff ;))

The computer is already running Windows, there's no need for Wine. Just the ability to launch a Windows program from within a Linux program would do.