Speaking about C, since I never went too deep into C++.
The original assertion was:
> ...gives a developer more insight into the actual machine...
For better or worse, Rust feels like a reference is a proper abstraction over a memory location whereas C drives home that it really is just a number. Perhaps I don't know Rust well enough but, without unsafe, I'm not sure how I would refer to an arbitrary memory location or use pointer arithmetic to access memory locations relative to a known memory location in Rust. Vector indexes in Rust appear to be more than just syntax sugar for addition whereas C allows both array[2] and 2[array]. And I know that Rust will prevent me from accessing memory that's already been freed since it's one of the selling points of the language.
Now you can argue that Rust is mostly saving you from unpleasant consequences, and you'd be right. But the fact that C forces you to understand those unpleasant consequences teaches you something about the nature of the underlying machine. C makes you realize just how much of a "wild west" situation exists at that level. It would be very easy for someone to learn Rust without being confronted with that fact.