I'm guessing that the red box is to help us avoid a classic mistake of people who are over-enthusiastic about their newfangled language: "Oh boy, alluks has a super fast lazy collect-redistribute-antimap function!" "Ah. What does that even mean?"

Also, it is worth keeping in mind that converting data to / from a form that is useable by a program can be a non-trivial computation. You can make a lot of np-complete problems look easy if you just convert the data in a clever way and ignore all that work. You might be able to justify ignoring that work if you can either preprocess the data or can efficiently pipeline data conversion in online scenarios.