They've resolutely stayed far away from the server market. Apple computers just won't be found serving web pages, operating cloud services, hosting storage arrays or anything. There are no rackmount Apples, no back-office Apples. They're all-in on the consumer market, and really concentrating on home users. Apples used in business settings work because of their high quality and excellent integration, and in spite of their non-enterprise focus.

If you try to spin up a macOS VM in the cloud, Avril Lavigne's band will invade your data center, and they will roll up to the most impressive rack, and film a music video there.

How many Unix workstations in a museum were from brands who were slummin' it, because they put big iron in every existing data center, and leveraged their resources to miniaturize all that and bring a mainframe or mini to every engineer's desk?

Also, Apple managed to tackle and really solve many features where Unix has a bad reputation. GUI/UX integration; hardware interfaces such as audiovisual, multimedia; software installation and management; sandboxing and strict access control for untrusted apps; integrated backup solutions.

Yes, it's mind-blowing that their "unofficial motto", "It Just Works" can be applied to something under the hood (FreeBSD) that is better known as the realm of tinkerers, hobbyists, and people whose tower PCs have excellent ventilation, because they don't even bother to fasten the case to the chassis anymore.

“The dominant UNIX workstation vendor” is Red Hat and nobody runs it on Macs. From a hardware perspective, that makes “the dominant UNIX workstation vendor” somebody like Dell, HP, or Lenovo. I am not sure who it is.

I know what you are saying. macOS is UNIX. macOS is a desktop OS. That makes macOS the leading desktop UNIX.

But the people that used to buy Sun, HP, and Apollo workstations for their engineers did not start buying them Macs instead. They moved to Windows. They moved to Linux. In both cases, they moved to commodity “beige box” hardware.

When UNIX workstations were a thing, the core market Apple was education, media (largely print back then but also audio / video ), and non-office desktop use. These are still their core markets.

Two things have changed for Apple: 1) media creation became a “normal” mainstream desktop user use case 2) the number of Linux developers exploded before the Linux desktop experience improved. Many of those Linux devs moved to Macs as an “also POSIX but useable as a desktop” option.

The rise in popularity of Apple hardware with “engineers” (mostly devs) happened after the collapse of the UNIX workstation market. It has more to do with the popularity of Linux as a server platform than it does with Apple as a desktop.

The same market forces have led to the creation of the Windows Subsystem for Linux. There are probably more developers using WSL than there are running macOS. So, from a certain view, desktop Windows may be the biggest UNIX workstation vendor.

Video editing has gone from a high-end hardware proposition to a normal desktop use case. Hence the rise of the “content-creator” class. It seems valid to say that those that would have used an SGI workstation in the past use Macs now, though Windows desktop users also edit a lot of video (being most of the market). But SGI was not really considered a “UNIX workstation” vendor back in the day. They were their own category. You would not buy an HP/UX system instead of an Octane and vice versa.

NeXT was not really a UNIX workstation either though that was Jobs vision. NeXT had quite a minor impact on the UNIX workstation market. Instead, it had a massive impact on the desktop market by being that software to “commodity” hardware via the sale of NeXT to Apple.

You are certainly right that Apple is the largest UNIX desktop vendor. By a lot. In fact, they basically invented that market. Other than NeXT, nobody really expected you to use a UNIX workstation as a regular desktop. Apple realized the NeXT vision in that regard. Linux is going there too but taking a lot longer.