Um no. Apart from being pretty coffee-script makes you stick with good object definition conventions, hides away unsafe comparisons (== vs ===), and is generally much more easily understood. This is one of coffeescript's main focus points : hide away the not so nice features of js, and highlight the good parts.

Yeah, but the language is what it is. It's out there, it's in all the browsers, it's not going away.

Rather than just learn to idiomatically write code that uses the nice features of js while avoiding the bad parts; we have two totally different notations to learn. That only causes further fragmentation.