1) Is dynamic like JavaScript, the learning curve for a seasoned developer such as you would be low and you'd get velocity quickly
2) Allows you to focus on the problem solving at hand rather than spending a bunch of time just build base classes to model your solution
3) Refactoring is easier as Clojure puts you on the road to pure functional programming, and your solution is not complected (or at least has low complection)
4) Has a nice interactive environment for prototyping/developing, much like some of the JavaScript tools out there
5) Can emit JavaScript for the browser using ClojureScript