There was a HN submission yesterday about another project of his (also in Clojure) and many of the comments were "Why is this made in Clojure?".
Unfortunately, a large segment of developers think there is no value in venturing beyond C-style languages.
Another dimension in recent years is the static type checking cult, whose adherents must warn everyone else in the cult whenever they spot any kind of dynamically typed programming language, e.g. causing a separate thread about the lack of static type checking in any comment section about a Clojure project.