Remember where that got us?
This stuff is all really cool and fun to work on, but instead maybe we should focus on changing the JS standard for the better since we always end up working in it anyways!
CoffeeScript was awesome at the time, and ahead of its time. JavaScript owes many of its new niceties to CoffeeScript.
Yes, please, let's advance the state of JS. And let's push the boundaries with other languages that don't have the backwards-compatibility constraints and corporate sluggishness that JavaScript does. Then take the best features and merge them into JS.
If you're working on a personal project, it might be a good idea to try out PureScript and learn from what it has to teach!