I was going for brevity but the downvotes tell me I said too little. CoffeeScript is a tool by and for experts. I don't know where people got the idea it is there to help newcomers. It's clearly an opinionated abstraction that is designed around removing the things that are grating to deal with as professional JS programmers on large code bases. The benefits on a line by line basis are small, but on a large project these small things (unfairly labelled as sugar) compound into large scale effects like a cleaner, leaner code base.
Part of your comment might be related to why CoffeeScript gets blowback -- there's an implication that if you're not using CoffeeScript, then you're not an expert.