[Animats]

Multics required unusual hardware that was expensive at the time. The hardware was abandoned by GE and taken over by Honeywell. Honeywell, which made thermostats then and makes thermostats now, was never a major player in computing. The big advantage of UNIX was that it runs on vanilla hardware.

UNIX is all wrong for microservices. Interprocess communication barely existed at first, and it's still mediocre. QNX did this right, with a true message-passing architecture, and a message-oriented network protocol. (Reliable, any-length message, not just raw UDP packets.) QNX continues to power many real-time systems, passing messages around.

[pjmlp]

The big advantage of UNIX was that AT&T wasn't allowed to sell it, and it was basically free beer available for a symbolic price, then the UNIX V6 annotated book did the rest.

If UNIX was closed source, sold at the same price as the competition, whatever hardware it run on would have not mattered at all.