Because I want make UIs and apps with open web standards, and JavaScript is the only practical language. CoffeeScript and other macro languages are cool, but currently there is no way to debug and step through the source.
I can't wait for the day that CoffeeScript has a robust debugger.
If debugger integration is a must-have feature for you, then fair enough. I'd make the opposite choice myself which is why the previous statement surprised me.
I can't wait for the day that CoffeeScript has a robust debugger.