Mind sharing a bit of info here - what do you mean and what Apple specifically did?
> everyone that only cares about UNIX/POSIX without religious attachment
I've personally helped to start with WSL for several persons, though I cannot say do they care on POSIX and UNIX as a concepts at all.
Suddenly everyone that only cared about some form of UNIX/POSIX, regardless of the source, went into droves into the Apple ecosystem.
These are the same folks that nowadays complain about leaving macOS for some Linux/BSD distribution, as they didn't grasp the actual Apple/NeXT developer culture (see Steve Jobs famous jabs at UNIX in its traditional form).
Microsoft with WSL is kind of approaching the same crowd, those of us that were already happy enough using a mix of VMWare Workstation, Virtual Box, cygwin/migwin, that have had enough of dual bottling, and the usual "everything works but".
From my personal experience and some opinions by others, even here on HN, WSL is the mix which provides best of two worlds for a lot of cases.