I think you are misunderstanding. Do you think that engineers designing the plumbing system of the F1 rocket engine knew pretty much anything about "compiler d

I think you are misunderstanding. Do you think that engineers designing the plumbing system of the F1 rocket engine knew pretty much anything about "compiler design" or "motherboard design"? What you are in fact observing is a human system's tendency to adapt to growing complexity. Human systems adapt to growing complexity by specializing it's members to particular skills (see https://en.wikipedia.org/wiki/Cognitive_specialization https://en.wikipedia.org/wiki/Cognitive_specialization). It's just a fact that way back then in the NeXT days, the computer was not as complex, the understanding of which was just about achievable by 1 human. Eventually, that metric exceeds 1. For the case of the first apple computer, it was ~1 (Wozniak), in the case of Apollo, it was >100. Cognitive Specialization is an aspect of all living things, but is very apparent in the Human species. Computers got more complex in just the same fashion as how farming went from a farmer, a bull, and a blacksmith, to gigantic conglomerates to make the fertilizer, tractors, watering system, etc., that comprise of >10,000 humans.