>you acknowledge that rustup not being in any given distro's repo isn't something that the Rust developers have control over

The lack is a consequence of the type of language rust developers chose to be. One that is constantly, rapidly (over just a few months) changing itself in forwards incompatible ways. Other languages don't really have this problem. Even c++ you only have breaking changes every 3-4 years which can be handled by repos. But 3 months old rustc in $distro repos is already fairly useless. Not because rust is a bad language, but because the types of people that write in rust are all bleeding edge early adopters and always use $latest when writing. In another decade or so when the rust developer demographics even out a bit it will probably be okay.