This is like a lot of "religious" language comparisons. It's written by someone who is intimately familiar with one and (appears to be) fleetingly familiar with the other.

The author makes some odd assumptions about CoffeeScript's intentions, ie language reduction and protecting against "evil code". All of this ignores the real main benefit, which is cleaner syntax, which means less finger typing and easier comprehension of a large and complex code base.

There was a time when JavaScript was the only real choice for browser-based web development. There were compilation tools like GWT, but they were heavyweight and generated the JavaScript equivalent of binary, completely detached from the source code. Now that the JavaScript++ languages are here (CoffeeScript, TypeScript) and well-supported in the browser thanks to source maps, I find it hard to imagine why people continue using raw JavaScript with all the bloated keywords, curly braces, etc (apart from legacy code bases). Usually it's because they haven't used anything else, and are content to focus on the negative of Coffee etc and stick to what they already know.