This article is the origin of the infamous joke about Haskell:
> Haskell gets some resistance due to the complexity of using monads to control side effects. Wadler tries to appease critics by explaining that "a monad is a monoid in the category of endofunctors, what's the problem?"
Hehe, that's actually how I ended up on this article, trying to understand what is meant by that statement in more detail.
I found that apparently the original is from here [0]. :)
> Haskell gets some resistance due to the complexity of using monads to control side effects. Wadler tries to appease critics by explaining that "a monad is a monoid in the category of endofunctors, what's the problem?"