Just imagine what Apple would do to the market if they also offered a full Linux support, but not Windows... They'd probably own some 70% of Linux market outright and also double its overall size overnight.
Apple wants to make money with services, however, and buying more devices in their ecosystem. Full Linux support would counteract the lock-in.
If apple came out with their own linux distro, with open drivers and a mainline kernel... A girl can dream!
Don't need to imagine, it did not take off, https://en.wikipedia.org/wiki/MkLinux
> Reception was mixed, focusing on the difficult installation process and the significant performance costs of the Mach kernel. Reviewers noted its potential as a "Unix killer", but that it required users to abandon the user-friendly Macintosh experience for a pure Linux environment.
They already cannibalized a lot of Linux users, developers mainly when they released MacOS X around year 2000.
Suddenly you could have a Unix, with pretty much the same CLI as Linux but without all the supported hardware/driver issues. Laptop sleep in particular was pretty finicky.
If MacOS didn't pick a Unix/BSD base, I'm pretty sure all the tech companies running Mac would be on Linux.