why not Rewrite It In Rust (RIIR)

Because C*,Hexa heck even Modern C++ is obviously better. By the way, careful usage of C++ gets all benefits of Rust without horrible amounts of memory leaks, anyone remember cosmic desktop? May be you shall not be fanatic rust user asking everyone to rewrite their stuff. https://www.youtube.com/watch?v=PG0wRb7eYms

Rust is an almost legacy literally 12-year old language appeared publicly in 2012 which means that its concepts may be outdated by modern standards.

No. This is a joke.

I don't, actually. I believe that those who spend their time asking people to rewrite their projects are probably not themselves active Rust developers, as those active devs are probably busy writing memory-safe code.