The link:

A Case Against Using CoffeeScript

The gist:

I make far greater use of the debugging tools in pure JavaScript because my brain can stay in the exact context it’s been in the whole time, in the code I wrote–not to mention I can copy/paste my code into the console to see if it works better right then.

Beautifying a language to make it more readable only to suffer the consequences of obfuscated output that is nearly impossible to debug is a recipe for disaster. I’ve been down this road too many times and it amazes me that people just don’t get it. Bytecode is a different story without the leaky abstraction.