Keep in mind this guy didn't even mention how javascript handles nulls. While nulls bypass typecheckers, typically a null + 1 throws an exception. Not so in javascript... null + 1 returns a 1 in javascript.
Null and NaN are different concepts with different trade-offs and different behavior when working with them. Nulls don't have special processor support[1] and are not part of a multilanguage, multiprocessor, international standard.
[1]: So far as I'm aware, though I'd love to read about it if I'm wrong.
[1]: So far as I'm aware, though I'd love to read about it if I'm wrong.