You know, I really don't have to justify my preference. It's not inherently "right" and you might even be able to define it as "wrong", but it's still my preference and that's what I'll base my purchasing decision on.
But, since you ask: I have a 16 GB card in my pocket computer, and a 32 GB flash drive in my pocket. Obviously, the flash drive can hold more than the pocket computer. Sometimes I want to access files on the flash drive. Do you seriously think I would choose to go to a desktop computer, transfer the files I need from the flash drive to the desktop, then from the desktop (DIRECTLY! -- as you put it) to the pocket computer?