Earlier quoted context omitted.
How do you copy a bunch of documents and pictures from and to a USB drive without a filesystem?
I'm not saying you don't need a filesystem. There are other ways to interact with data besides a file browser. On the iPad, I can use the official Photos app (or any of the other photo apps) to get my photos where they need to go, whether that's a phone, computer, website or printer. I don't read my email by going into the "My Emails" folder on my C:\ drive, I access my email through a UI specifically made for access…
How do I tell iTunes (or any other music player) to import some of the music on my USB drive? iTunes doesn't even allow you to do that with iPods...