It is more true for Coffeescript, because Coffeescript is so closely tied to specific Javascript problems and idioms that it makes it more of JS shorthand than

It is more true for Coffeescript, because Coffeescript is so closely tied to specific Javascript problems and idioms that it makes it more of JS shorthand than an actual new language. It's very different than understanding .NET (or Mono, for that matter) to write C#, or understanding the JVM to write Clojure.