As a rust dev I'm just as perplexed. I've seen preprocessors and stuff like tailwind being rewritten in Rust aswell. Why though (
Overall Rust and its community have many traits that make them very approachable to people not expected to know anything about systems programming, namely:
-Package manager with a familiar philosophy behind it (and not the sort of hell you have to deal with setting up a C++ development environment).
-Outputs WASM without much bureaucracy and advertises it.
-Friendly compiler messages. I don't recall seeing "perhaps" in a compiler error message before.
The people designing Rust put much effort into making the language as approachable as possible and that's the net effect.
That is not to say this is going to be necessarily successful, but so far the enthusiasm is there.
That doesn’t mean it couldn’t be done in other languages, but it’s a weighing of trade-offs. And of course, groups of people, such as developers on socials, are quite sensitive to popularity.
Having built a compiler and typechecker in Rust, I don't know if I'd say that it was "quite good" for it. Going back, I'd still do it again, but it wasn't exactly a cakewalk. Rust's lifetime rules and visceral hatred of referential structs did not make my life easy at all. I definitely took the easy way out with a lot of string copies too.
a) speed. On large codebases each preprocessor (and there may be many) can take a long time
b) Rust has several features which make it quite suitable for writing pasrers and suchlike
Perhaps "speed boost" would be a better alternative for your intended meaning.