This is what most people who complain about Rust rewrites don't get. It's not just about memory safety and some new language features. Rust simply did a lot of things right and is nice to work with. New developers actually join Rust projects while old tools written in C struggle to survive.

[–] abc@suppo.fi 6 points 6 hours ago

Yup. I'm an old fart who learned C as my first real language. Rust is just fun.

[–] Ephera@lemmy.ml 10 points 13 hours ago

Yeah, I enjoyed when fish shell did their rewrite and people were arguing whether it makes sense technologically, like it's a mature codebase, so it's not likely to reduce the number of bugs and yadda yadda yadda.

None of this mattered, because fish is developed by a group of hobbyists. They didn't want to continue developing in C++, because it was a pain in the ass. And for sure, one of the reasons they wanted to switch to Rust is because it's new and exciting.
These reasons are perfectly valid, because they're volunteers. If they're not having fun, then they will just developing.