CoffeeScript can't really claim that "it's just javascript" either. I'd have to figure out how to hook up the CoffeeScript compiler into every single one of my workflows where I use javascript.

For example, I use swank (https://github.com/swank-js/swank-js) to send javascript to the current page in my browser from Emacs. I couldn't live without it. I'd have to figure out how to dynamically compile it, and I'm not sure if there's any restrictions with piece-meal compilation.

It's definitely a separate community and I'd lose out on lots of good tools if I had to use it. I'm glad nobody wants to use it where I work.