It sadly continues the same abuse of English that's present in more modern Windows.

The word order makes it seems that it's a "Windows subsystem," rather than a "subsystem for Linux," that just happens to be in Windows.

If English used more word cases, Microsoft's unusual choice of word order probably would have been acceptable. But probably, some half-wit VP/PM decided that everything Windows must start with the word "Windows," and here me are.

Even "Windows Linux Subsystem" would be far more clear, and one word shorter, even if it is ugly.