I don't mind searching to find what I want, but I find myself uncomfortable if I can't then see where it "really" is. In a universe with just tags/labels, it doesn't feel like it's anywhere.
I can avoid that by having my files in a content-based-addressing pool with metainformation.
I'm not organized by nature, but I need some kind of hierarchy for my computer files. There's too much.
Some collections of my files are accessed entirely hierarchically, others are not, I don't think I should have to pick a single paradigm for all my files.