I think claims of improved productivity when switching to Clojure have a lot to do with the person making those claims and where they are coming from.

I see Clojure as almost sub-set of JavaScript bundled with a great standard library akin to Lodash or Ramda. You can write very Clojure-y functional code with JavaScript, and if that is what you are already used to doing, than you might not see a big difference in switching to Clojure.

But JavaScript is a bit of a kitchen sink. You want classes, you got em. You want prototypes, you got em. Functional programming, sure. This wide mix of language features means that everyone’s experience with the language will be different, and if somebody is coming from a very object-oriented background, being exposed to the data-oriented functional approach of Clojure can be an eye-opener.

Personally, using Clojure had a huge impact on how I approach development (having from from a traditional C#/Java background). I consider myself much more productive now and view problems in a completely different light. I don’t write Clojure for work, I’m pretty much full-time Node.js these days, but I credit Clojure with changing my development practices for the better.

I guess what I’m saying is that it’s not necessarily Clojure-the-language that make people feel more productive, but maybe it’s just the development style that Clojure almost forces upon people that makes them feel more productive.

(And personally, I just love the elegance of a language with such minimal syntax... and an abundance of parens)