Monads are important in providing well-defined semantics for code. They are a way of taking imperative code and making it functional; the semantics of functional computation are much easier to define than those of imperative code. If you were interested in proving your program correct with a deductive proof (rather than, say, statistically acceptable with tests) , monads would be very important to you.

They weren't designed to provide useful design patterns. That's why articles attempting to demonstrate them as useful design patterns often seem artificial. But I think that as the art of software engineering progresses, the problems they solve will become more important.