What all these C programmers are pointing out is 2 fold:

- Making a Turing machine have deterministic and predictable results is hard.

- Modern hardware is complex and getting all hardware to behave the same way requires a strong mathematical abstraction.

C was never intended to be a fully defined mathematical abstraction. It was a language which was easy to write a compiler for. That's its original strength. Trying to make it something it isn't is the problem. Either choose a language which does have such abstractions or understand the drawbacks of the tool you are using.

Right tool for the right job.