This is due to a lack of being able to think abstractly, not with files and hierarchical folders specifically (which is a specific kind of abstraction), and I find people's frustration frustrating myself. If you gave the same person a print of a photo, and asked them to resize and fax, they'd have no trouble doing so with a photocopier and a fax machine (other than that these devices are often complex themselves, but that has nothing to do with the photo print as portable storage, which is all a file is).