I'd say this "difficult-to-debug" attitude comes from those who did not actually tried to work with CoffeeScript and just think that would be the case.
We have a lot of code in it already and debugging was never an issue.
Sorry, but wouldn't that defy the purpose? You can only use JavaScript client-side, and I assume it would take a lot of time, effort, and "why" to make browsers ship parsers for other languages.
I'd hardly characterise coffeescript generated js as difficult to debug (even the OO flavoured bits). My experience and that of most others I've seen online is that the mapping from the js that you debug back to the coffeescript that generated is trivially done in your head.
I can write a scrapper for any text-based website within an hour. As far as I know, site scrapping can't be prevented. You could make it harder, though.
The syntax is beautiful, it had potential; why be a difficult-to-debug JavaScript 'compiler' instead?