I think the issue is that, from a user perspective, the implementation details of the kernel and base OS doesn’t matter. As long as it’s sanely implemented and doesn’t impose onerous limitations, it should just get out of the way. The vendor can implement it however they like, with whatever technologies they like, and as long as it supports featureful applications users shouldn’t need to care.

The reason Unix was so successful was precisely because it was simple and portable a d designed to get out of the way. It was as unremarkable as possible, by design. All the interesting stuff is left to application developers. You want to implement a relational file system, go ahead. You want to develop your own GUI layer, fine. Compared to the other major OSes of the day like VMS, Pick, PrimeOS, etc it’s as unoppinionated as possible. Likewise with C, which is intended to be as low level and paradigmless as they could. Just an abstraction over assembler just as Unix is a thin abstraction over the hardware.