A well-written literate program is a joy to work with. To be able to genuinely understand a complex program's design by reading well-written prose which forms part of the source code. Literally reading code like a book, finding that it effectively has a plot and characters with understandable motivations, properly introduced and their places and relationships clearly understood. Done right, it can work so well.

The only software I ever worked on in which the customer never reported a single bug was written entirely in literate code.

The software I work on now is so much at the other end of the scale that sometimes when the customer reports something, there is a signficant period of investigation before deciding if it's a bug or if that's how it's meant to work.