he's missed the point. people aren't saying that "CoffeeScript is a priori somehow wrong or inferior or a bad choice". Coffeescript is an abstraction, and abstractions have potential to leak, so some people are questioning whether the benefits of coffeescript - namely, prettier code - are "worth it" for production-scale projects.<p>as your project gets big, does coffeescript help us write more maintainable code, better abstract our solutions so we can keep less things in our head at once, resulting in higher agility and fewer bugs? When you look at the deep reasons why a large codebase went sour, you're not blaming it on things like list comprehensions, you're blaming it on things like "Java strong-arms us towards building abstractions with only OOP, which over the course of a few years builds into indecipherable layers of implementation inheritance, causing high defect rates and much decreased agility".<p>The difference between CoffeeScript and Javascript, in terms of what a team can accomplish, hasn't been proven in production-scale projects. they may be, or maybe only for some teams, or maybe they aren't, but you can't debate something without being able to articulate the opponent's position.<p>update: interestingly, ClojureScript may be a language where the productivity delta from javascript is much larger, and is better worth it. clojurescript introduces new ideas and idioms to the js community, where coffeescript is an incremental update to javascript with no new ideas.