> Notice that your 5 - 10 lines of JS don't let you write code that works in any monad, whereas I can easily write

Maybe, maybe not. Depends on your requirements, really. The core language might never get this, but these 5-10 lines of code do some very important things:

- they explain monads faster and clearer than any of the countless monad tutorials that exist for Haskell

- they demystify monads and show that: hey, you've probably been writing monads all along (and re-implemented them yourself countless of times, no doubt)

- they (by necessity) dumb down the jargon-heavy lingo for easy consumption by average Joes like me :)

Edit: that page in particular has also shown me that I have used easily half of Haskell's things (functors of all flavors, monads, comonads, etc. etc. etc.) countless times over the years in Javascript and Erlang. I didn't even know I did, because no one scared me off with the theory, and strange explanations and names :)