If you look at the market shares, you’ll quickly realize that this would mean abandoning all the BSDs, Haiku, Hurd, all the obscure Linux distributions and so on.

Just support macOS, RHEL/SLES, Debian, Ubuntu and Windows.

Everything else gets tagged with “UNSUPPORTED/WONTFIX”.

But please don’t complain when your favorite operating system is not supported.

Or, you know, we could just stop trying to tell others what targets to use.

And, FWIW, Rust is actually getting support for more architectures thanks to the GCC codegen and GCC frontend.