Selling UNIX underpinning was just a marketing move for willing to betray GNU/Linux and BSD in name of a better laptop experience, instead of helping OEMs selling their stuff.
Something that NeXT also did against the Sun workstations market.
On Linux side of the this kind of security measures never work, because the moment someone introduces something like this, the distribution gets forked.
It works on ChromeOS and Android, because it hardly matters to userspace that Linux is the actual kernel, Google could embark (and it is actually) in a kernel replacement project and most stuff would just work.
One cannot give the money instead to Apple and then come back complain that they were mislead.
NeXTSTEP was also a true UNIX, that wasn't why most business bought it, rather Renderman and other graphical based tooling.
I have used Apple platforms on and off since the LC II days, their commercial view was always quite clear to me.
They do GNU/Linux, but BSDs should probably work on their hardware, as mentioned on this old post (sorry in German).
Or by getting in touch with companies like os-cillation.
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