A C data structure is never a disaster of "thread unsafety" if, like most data structures, you don't use it across threads. Any Rust data structure which is Send and Sync, translated literally into C, is just as safe in C to read (or write in the rare cases &Structure is mutable) across threads, and create in one thread and destroy in another. It's only thread-unsafe if
used in a thread-unsafe manner (and all Rust adds for non-multithreaded data structures is checks to prevent users from mutating across threads, though its pattern of "one handle per thread" is helpful for structures
designed to be mutated across threads).
And C is not a dick-and-leg removal device, it's a direct representation of runtime semantics (aside from signed integer overflow which is avoidable, type-based alias analysis which is rare, etc.), and any sound Rust code which doesn't transmute types can be compiled into equally UB-free C code, and even Rust which commits UB by violating SB (many unsafe libraries) can be transpiled into UB-free C code as long as you don't use `restrict` when inappropriate. Rust is merely a possible way to organize a program to avoid UB, to be followed when helpful (RAII, catching use-after-free in application logic, avoiding reference counting errors, multithreading) and replaced when it impedes writing low-level code. It's not a religion where apostasy is punished by castration.
I'm criticizing Stacked Borrows because I've seen more than enough evidence that it's an unreasonably stringent memory model for writing unsafe code. Please stop putting words in my mouth and misrepresenting my positions as profanity-laced straw men, like "not giving a single shit about correctness".