I think the point is that many HN posts mention "I made X in Rust", whereas similar projects using Go or Javascript don't mention the language in the post title

I think the point is that many HN posts mention "I made X in Rust", whereas similar projects using Go or Javascript don't mention the language in the post title. So it does seem like Rust users tend to like vocalizing it. I also think this study is slightly biased towards new and hip languages. For example, less people are going to vocalize that their new web app is made with Javascript, because that's already the assumption. But Elixir will almost certainly be mentioned