I don't get it. Look at Jade, Stylus ... pythonesque isn't it. The same arguments that are made against CoffeeScript certainly can be argued for those sugar syntax alternatives of HTML and CSS respectively. Some will argue ad nauseum for not using semicolons and then hate on CoffeeScript.

I've had no problems debugging or understanding CoffeeScript and while I'm not at the level of a Jon Resig, I can more than hold my own with Javascript. CoffeeScript is just syntax and generally safer than plain Javascript. It will declare vars for you if your forget. It will use an optimized for loop. It will put a wrapper around code to minimize leaks ...