The situation of CoffeeScript and Javascript isn't the same. All the existing debugging tool will only show you Javascript code when you want to debug. C is different on that point. Almost all (if not all) the IDE in which you can code and debug allow you to debug without having to ever see any line of assembly. You don't have to understand the generated assembly code to code in C, because you will never have to look at it.
The situation of CoffeeScript would be like C if the only way to debug C code was to debug it in assembly.
The situation of CoffeeScript would be like C if the only way to debug C code was to debug it in assembly.