It matters for the same reason that "X written in Rust" or "which companies are using Lisp?" matters: some people refuse to give Lisp a look unless every F500 company has at least 3 major projects written in it.
Nothing is wrong with this. There are crapload of languages and very little benefit from a practical standpoint for a single person to use them all. They're just tools. Some are better, some are worse and some are highly specialized. What is being built is important, not how.