I would say, there is some complexity in reading (and writing) the thing. But there is probably not as much complexity in using it. And you are explicitly codifying the complexity in one place, that would presumably still exist in a dynamically typed language, just implicitly, and likely spread out across the code. This looks pretty nice to me at a glance, just like anything once you write a few of them and come across a few in the wild and take the time to pick them apart they no longer seem so scary.
