I agree that it's not a big deal for most folks, who only deal with a book or two at a time, but it's still pretty much a no-brainer to provide a hierarchical file system -- I mean
everything has a hierarchical file system -- there are even refrigerators with them these days!
While the flat file system may not be a problem for most folks (and it doesn't affect me all that often), it's still pretty astounding that they settled for a file system that actually
dissuades folks from carrying more than a dozen or so books at a time -- they advertise that you it has room for ~90 books, so they must have expected folks to carry more than a few. I just don't get it.
Maybe there
is some arcane hardware/software peculiarity that makes this difficult, but I still don't get it.