Why Do All the Great Node.js Developers Hate CoffeeScript?

I wouldn't say they hate it it's just that they don't use it. Coffee isn't bad but if a slight majority of module devs don't use Coffee it doesn't make sense to use it either in order to stay interoperable with Node's entire ecosystem. When Node started Coffee was strong and hyped and it wasn't clear if Coffee was going to be used with Node.

IMO JS syntax is ok and I prefer it over Coffee. Coffee offers nice language constructs like classes but I can read easier native JS code than Coffee. Most of coding is about thinking and reading/looking at your code or code of other modules—writing code is the smallest part and the result of the former. Thus, the time savings I have with writing Coffee are small. Coffee is very similar to Ruby, thus popular with Ruby des but this pretty dense code is not everyone's taste.