I don’t see this that bad at all.
I think MS can not destroy Linux. Can you imagine, for example Debian people to quit using/contributing Debian because switch to Mariner?
I cannot… 
But I can imagine, that one time Windows (say Windows 31.415926536) will be based on a Linux kernel, and Windows will be technically just a DE, like KDE, or GNOME.
That won’t mean destroying Linux, but the opposite.
Of course I may be wrong 