Of course you can reduce the JS verbosity with JSX instead... which again is introducing a pre-processor to the mix (one I personally am not a fan of, but w/e).
ES6 adds some sweet stuff for sure, but IMO it doesn't make JS a pleasure to work with yet (which seems to be the argument?).
I'm willing to bet it's not going to reduce the count in this list by much. https://github.com/jashkenas/coffeescript/wiki/list-of-langu...
I'm comfortable writing either as I'm sure many are, but when given the choice I opt for CoffeeScript.
P.S. Good luck telling someone using ClojureScript that they should switch back to Javascript.