Most documentation is non-linear. Functions are documented without regard to their calls, etc. The trouble with them is that it's hard to scale up to large sub-systems. If you are modifying some cross-cutting facet of a large system, it's often hard to find the right place to add an illuminating comment given all the different places you are modifying simultaneously. Literate programming is a way to give that place by introducing linear narrative structure in documentation. It can be quite valuable at large scales.

That said, my critique: http://akkartik.name/post/literate-programming (I actually read many of the programs in OP to write that.)