[leif]

That's not the point, the point is that Maybe is the right way to handle what nil (or None or null) fails to handle properly. Scala gets it right too, IIRC, with Nullable.

1. A "null" instance of one type should not be conflated with a "null" instance of a separate type. 2. By type-wrapping in a Maybe, you declare where you need to be able to handle nulls and where you are free to ignore them (but can never pass them in). You confine the null to specific regions of your code. 3. You force your code's clients to think about the null case wherever you make it visible.

[Locke1689]

Maybe is really just a special case of Either, where it optimizes for the situation where the second return type is "failure." The type of Either is necessary because proper type theory requires a container type to wrap two types. This is immediately obvious if you try to write the type signature for any function which has a return arity of one.