Rust is far from being "an obscure programming language", and I'm pretty sure there are people here on HN that may find useful to browse the source code of a real world application in Rust (and who don't give a shit about the software per se).

Such comment would have made sense if this software was promoted in a more general board/website, but HN audience is mostly compound by developers, so technical aspects matter. On top of that, it also gives an idea about the popularity of a programming language.