That's one point. There's quite some domains where it's illegal to send production data across a border, especially if the target country has lesser protections (think safe harbor). I can't see how that's magically not going to happen if Win10 is used with its spyware in place.
Let's not forget professionals with obligations of privacy, such as lawyers, attorneys, doctors etc. I don't know how e.g. hospitals can go down the Windows road, or how medical equipment can be run with this OS.
And let's not forget either that per EULA, MS Windows is not to be used in critical infrastructure - there's plenty of examples where it's used anyway, including US warships.