[qu1j0t3]

Recursion and iteration are equivalent, so it's not much of a stretch to call it a core concept (for more, see SICP & the lambda calculus). It is the only form of iteration available in functional programming.

Monads are not only a good abstraction, they are essential* if we are to move away from haphazard construction. Normal programmers have invented them many times; as the truism goes, you have have even "invented" them yourself.

Remember when function pointers seemed tricky and unnecessary? Remember when closures seemed tricky and unnecessary? Yeah. One day you're going to see monads in the same way.

* - Functional programming => programming with pure functions.