As someone who actually works with a lot of basic computer users, you are incorrect.
Nobody has ever struggled to understand files or folders. My 80 year old aunt has a preference for the names of her email folders. My 11 year old nephew has a sorting system for his little game mods.
No the main issue is exclusively "crap". To quote my mom on a recent call: "How do I make this thing go away?" (It was a notification about some new cloud service).
Breaking user patterns is a close second - especially anything to do with file management.