Wolfgang Jeltsch wrote:

So instead of arguing whether join or
(>>=) is easier, more natural or whatever, just let us make both a
method of Monad.

Does anyone want to comment on my comparison with restricted monads, where '>>=' can be defined, but 'join' cannot?

I am in favor of being able to choose between join and >>= when defining Monad instances and don't consider consistency with RMonad very important.