Why would I learn something which doesn't offer me any value? CoffeeScript is literally syntactical sugar, which I believe, adds levels of indirection to the code and makes it more difficult long-term to support, read, and develop. Not only that, but JavaScript's evolution has made nearly every reason to use it moot.

Also FWIW-- I've done vastly more native and server-side programming over the last... oh, seven years than "web." So... I don't think this is something with "web developers."