I've been in situations where I had to supply a digital version of a signed document but the person asking for it required that it be physically printed off to be signed and then scanned back in. Some policy thing. I think it would technically be fraud to use this but that's one use I thought of.
The description however seems like the creator just likes how scanned documents look. They describe it like how analogue music fans describe vinyl records. I guess everything is nostalgic to someone out there eventually.
For some value of practical, I could see it being useful in making handouts for an RPG where the handout is supposed to be a photocopy of a section of some rare book the players need to scan for clues.
This is in fact useful for people who demand you to print out and sign contracts. Did so many times in the past, using some ghostscript+imagemagick scripting to avoid the cargo culturing.
Sometimes companies demand you print/sign/scan a document.
Typically when I send a form I will do as much as possible in a PDF editor, including the signature. Most of the world is in denial about how electronic documents, especially scanned ones, work, so you have to play along to stop them from getting upset.