What CoffeeScript did was lodge the idea in people's heads that JavaScript can be treated as an assembly language to compile higher-level languages into. I'll bet many programmers' attitudes toward ES6 are: someone will write a compiler for my language, and I'll just use that.
It seems better to treat JavaScript as admittedly not being the most powerful language in the world, and to treat the standard as a kind of RFC that only compiler writers have to think about. For most programmers it works to just use CoffeeScript (or Lisp or anything) without worrying about standards, just as JavaScript programmers don't need to worry about how their processor works.
In fact, maybe Javascript is too powerfull. It would be interesting to get a stack machine emulation in the browser, with an standard set of libraries/tools for native access to the DOM and emulators for most interpreted languages out there.
Kind of a Java plugin that runs on web, instead of just tunneling through it.
It seems better to treat JavaScript as admittedly not being the most powerful language in the world, and to treat the standard as a kind of RFC that only compiler writers have to think about. For most programmers it works to just use CoffeeScript (or Lisp or anything) without worrying about standards, just as JavaScript programmers don't need to worry about how their processor works.