Unix is completely inapplicable to this environment which is inherently managed and intraprocess. Why not send an object saying what you want instead of a plain C struct, or worse a bunch of ints? How do we handle ownership across these boundaries? Why should two high level components be forced to squeeze into a primitive bottleneck between them?

Don't get me wrong: I think C is cute and fills a niche decently well. But that niche is not the one we have here.

The reasons why Unix displaced a bunch of more elegant systems were downward scalability, free distribution, and positioning to take advantage of network effects. Quality was secondary, especially with multiprocessing and networking where a lot had to change, and the designs were not always good.