This is a really interesting phrasing:
>> There were problems within Apple that made the development of the OS nearly impossible, and to solve these problems Apple sought to purchase something that was close to their own vision.
I think the truth is that Apple, and Apple + IBM worked on operating systems in this period and had trouble making a good one. Why it is hard for a mature company with legacy systems to create a new operating system is a difficult thing to explain. But it is not unusual. And worth understanding for people who want to innovate in large organizations.
> Why it is hard for a mature company with legacy systems to create a new operating system is a difficult thing to explain
In general, the hardest problem for such companies is backwards compatibility.
In the case of Apple, it was doubly so: they tried to build a pre-emptive multitasking operating system with memory protection that was backwards compatible (both for applications and system extensions) with an existing OS that had cooperative multitasking, did not have memory protection, and had OS support for patching system calls (a feature that allowed third parties to develop of such things as Switcher (https://www.folklore.org/StoryView.py?project=Macintosh&stor...), After Dark, Adobe Font Manager, and RAM Doubler).
It is easier to achieve your architectural goals with greenfield development than modifying an existing system. However.. once you have an existing system, why are you going to throw the whole thing out, waste all those man-hours spent to make the thing, discard all the bugfixes you had to sweat over. It is very hard for a large organization to justify making something new.
It is the reason IBM had to set up a secret ninja tiger team to make the pc. They tried a few times before, and ended up with really nice systems, far nicer than the pc. but they cost 10,000 dollars, in 1980, you are not gong to conquer the small business market for computers with a 10,000 dollar machine. so they set up a secret team, far away from the rest of the ibm mothership apparatus with the mission to make the cheapest computer possible, and they did, it cost 3,000 dollars had nothing compatible with any other ibm and sold like hotcakes.
> Why it is hard for a mature company with legacy systems to create a new operating system is a difficult thing to explain.
My theory is that you can't really _plan_ how to create and spread an OS: You need to put a dedicated enough person with enough time to write an interesting prototype that would brings you a subsequent advantage. And of course, you need the peoples that will judge wisely about the long run future of this prototype (remember Linux being considered bad?). After this, the prototype have to be mature enough for developers to and hardware makers to support it.
That's a lot of _if_, and I suspect most OS (and in some way, softwares and language) are spontaneous creations that answer a need and become _good_ as a consequence of being used.
I think the truth is that Apple, and Apple + IBM worked on operating systems in this period and had trouble making a good one. Why it is hard for a mature company with legacy systems to create a new operating system is a difficult thing to explain. But it is not unusual. And worth understanding for people who want to innovate in large organizations.