Why do some admissions processes request an exhaustive list of jobs held?
My suspicion would be that the school with such a requirement has a very narrow age window it desires in its graduate students, or at minimum desires that the ink still be wet on their baccalaureate diplomas -- the "train them up young" approach. Listing all post-high-school jobs is not usually terribly onerous for the typical 23-year-old.

I can't speak to how appropriate this is across disciplines. I can only say that where I am we only ask for a résumé and do not specify how far into the past it need go, because we value learners of all ages.