UNIX support was never a goal for macOS, neither for NeXT, rather a nice way to bring developers from Sun and SGI into their platforms.
The business value for developers was always the Objective-C libraries, which is quite clear from most presentations done by Jobs, some of them available on YouTube.
It is as if some people needed this week's presentation to wake up for the real Apple culture, that goes back to the days when they kind of toyed around with A/UX.
I have no delusions about Apple culture. But apparently you're forgetting that Apple heavily marketed OSX's association with UNIX after the merge with NeXT, and that it made a lot of noise about how the Mac would be the best UNIX workstation ever.
I lived through those years and saw the same presentations you mentioned - some on VHS tapes that were shipped to us after the events. There was no toying about OSX as a workstation, it was even on the sales pitch guides.
The real Apple culture was Object Pascal, Common Lisp, Hypercard, Dylan, Newton, MacApp, PowerPlant, QuickDraw,...
Now they have money and they actually need is macOS, iOS, tvOS and watchOS developers, not UNIX developers deploying code on GNU/Linux servers.
Many of our customers follow similar patterns, I hardly see new desktops being deployed, so I have some sympathy for Apple thinking that it might not be worthwhile to keep doing them.
Also it sounds like you want the ability to develop for osx on a non-osx device. That seems counterintuitive.