Bootstrapping of the rustc compiler from scratch is a very different experience than using the language as a user. Bootstrapping requires building a C++ mrustc proto-compiler, which is where the tons of flags are needed. The rustc compiler has a custom multi-stage build system to make it and its standard library built with itself, which multiplies the time it takes. It's designed to be consistent and optimized, since most users download a pre-built binary.
However, once you bootstrap it (or willing to trust someone who did), it's a breeze to build Rust projects with Cargo: `cargo build` just works with no extra flags for the majority of projects. The only finicky builds are ones that rely on C or C++ deps.
Calling your users idiots is not a good look for a maintainer. I don't know offhand what distro you maintain but I sincerely hope I never have to deal with someone this hostile.
You're harshly judging the entire language based on ease of compiling a 3rd party C++ compiler and the C11 code it emits. These gnarly build commands don't even come from the Rust project, and aren't using the Rust language.
(I assume you use mrustc, and you're not going the masochist route of recreating all the development steps starting from a 15-year-old Ocaml-based prototype of a language that wasn't Rust yet).
It's fair to say that bootstrapping of Rust sucks. It really does. The non-Rust bootstrap compiler doesn't get even a fraction of the polish that rustc and Cargo get. But it's not representative of how Rust and Cargo work for basically everyone in the world except you (and a couple of other maintainers who chose to do an independent bootstrap from scratch). Bootstrapping is a one-off pain, and then building Rust with a Rust-based compiler is nice and easy.
It'd be nice to have a cleaner bootstrap story for Rust, but it will take a while (waiting for gccrs C++ reimplementation to advance enough to replace mrustc).
Rust is pragmatic about its implementation. The goal isn't some ideological purity (despite the reputation Rust has), but to empower users to make safe and efficient systems software. LLVM works well for that, so replacing it isn't a priority. The cranelift backend exists to make debug builds faster.
However, once you bootstrap it (or willing to trust someone who did), it's a breeze to build Rust projects with Cargo: `cargo build` just works with no extra flags for the majority of projects. The only finicky builds are ones that rely on C or C++ deps.