Ah, but Rust will help reduce security problems! Even if the number of potential Linux contributors is cut to a fraction due to the difficulty in learning two languages with steep learning curves, better security makes it all worth it.
Given all the CVEs that arise due to buffer overflows and UAF, it's not working very well. Safe Rust makes those classes of problems Just Go Away.
> Do you think inexperienced programmers could build it given a "safer instrument"?
Inexperienced programmers can get started without the near vertical learning curve C presents. Just wrapping your head around pointers scares many programmers off, and even once you grok pointers, attempting to use them correctly is a minefield. This makes kernel hacking daunting for the average dev. Rust gives them an onramp.
> How many junior devs understand intricacies of basic OS-level locking, not mentioning Paxos and other scary algorithms whose formal correctness can't be even proven in theory?
Not very many... but junior devs don't need to work on that stuff. They can make more peripheral contributions -- fixes to device or file system drivers, etc. -- while they're building their skills, completely confident that they will not make a class of stupid but very common and dangerous memory errors. Not so with C! As I said, not even great programmers can be relied upon to write safe C code -- the model presented by C is just that abstruse.