> Going back to plain JavaScript might not be quite as concise, but the fact that the code always does exactly what you want it to, no surprises (as long as you know the language), let me program in peace again.

I'm sympathetic to your point, but this seems entirely wrong in context, because JS exhibits all the flaws you decry and more.

JS is often an ambiguous language, and often behaves poorly in edge cases. Even in the specific example (variable scope) the JS rules are arcane, poorly documented, confuse the hell out of even experienced JS programmers, and are hard to debug. Unless your argument boils down to "I know JS much better than Coffeescript, so its edge cases are less surprising to me", where in the world is the "win" from switching to Javascript from Coffeescript?

For what its worth, I've used Coffeescript more than you, and I find it does have the problems you state, as do pretty much all languages; it's one of degree. Coffeescript is worse than, eg, lua, but better than, eg, Javascript. And of the feasible languages to write code that will run in the browser, Coffeescript is the best choice (if the decision is purely based on "will my code do what I want/are edge cases going to bite me unpleasantly"). But that's just my personal experience. :)