“nobody” means: those who have big projects with multiple .rs files but no Makefile, no cargo.toml, no build.sh, nothing, only the .rs files. Can you point to a project that does that? That’s the point. We don’t have default rustc on all machines and repositories. In example in Archlinux repositories there is not package rustc only and its standard libraries to install. That’s why most people don’t do it. You can’t fault the missing projects are missing, because the infrastructure is not there yet.