ISTM the author's "pure javascript" version of the horse/snake example is not solving the same problem as the CoffeeScript one.

In the CS code, the association between the object and it's type of motion (galloping/slithering) is made at construction time (via the implementation of "move" associated with the object), and in the "pure javascript" code it is made at the call site for "move".

This seems like such a fundamental difference that it becomes a little difficult to take the rest of the argument seriously.