Moreover he's doing Python web development - I like Python and it's perfect for web development, but it's not exactly close to the metal.
Emacs works fine for python-based web development. I don't use it myself, but there's no particular reason it wouldn't work, and AquaMacs is actually a very pleasant version of Emacs, both true to Emacs's spirit and nicely integrated with OSX. I agree that in general Emacs isn't the best tool for every job, but there is historical precedent for using it to develop a language with strong dynamic types. It's clearly not the best choice for Java-based web development (I can say that with a certain amount of experience), but that doesn't mean it's the worst choice for all web development either.