Memory safety by default in kernel sounds like a good idea :). However I don't think that C is being _replaced_ by Rust code, it's rather that more independent parts that don't need to deeply integrate with the existing C constructs can be written in a memory safe language, and IMO that's a fine tradeoff

Definitely not. Rust gives you a tangible benefit in terms of correctness. It's such a valuable benefit that it outweighs the burden of incorporating a new language in the kernel, with all that comes with it.

Zig offers no such thing. It would be a like-for-like replacement of an unsafe old language with an unsafe new one. May even be a better language, but that's not enough reason to overcome the burden.

I believe Rust is mainly being used for driver development, which seems a great fit (there's so many people of different skill levels who write Linux drivers, so this should help avoid bad driver code being exploited). It may also end up in the core systems, but it also might not fit there as well.

And “if you enjoy C++/if you enjoy C” are gross oversimplifications.

And Zig isn't stable yet