I became a Clojure fan-boy over the course of the last year but one issue that seems to keep popping up when I discuss it with my JavaScript/Node.js co-workers is "Clojure runs on the JVM? Not interested".
Setting aside the technical validity of that opinion (JVM vs. Node.js), it made me wonder if there might be more interest in Clojure from the JavaScript world if they knew they could use ClojureScript for both the front-end and the back-end (on Node.js).
The JVM is still a great choice for all those reasons, but its a little heavier than Node.js which specializes in IO bound use cases (i.e. the back-end-for-front-ends that sit between the browser and the heavyweight back-end systems). Node.js is also probably better suited for smaller services, lambdas, and other light-weight scenarios (IOT?).
I'm interested in promoting a full-stack approach to ClojureScript because the JavaScript/Node.js ecosystem is everything that the Java ecosystem was 15 years ago. It has lots of developers, lots of libraries, and a "bad" language. And by sticking with Node.js, its one less hurdle for JavaScript developers to clear when learning ClojureScript. They still get to use all the same libraries they did before (via ClojureScript's great interop), and the runtime characteristics they are used to. Plus, if they then decide to start looking at Clojure on the JVM in the future, they will have already learned the language.
I later tried to learn F# and while the syntax was foreign, it turned out that it was MUCH easier to write FP code because the language had native operators for composition, etc. The code was also much easier to read.
I think it would be great if JavaScript got some FP syntax natively (see the pattern matching proposal). But hacking functional principals using arrays and helper functions just leads to hard to read code, especially for people not familiar with the specific FP library you chose to use.