For the youngsters among you, this is in fact a very old design discipline which was used to organise what were called books. Unlike books, which were bound collections of fixed size pages (done for compactness and strength), this is an emulation of what used to be called a scroll, a much older form of organising text which was abandoned as impractical as soon as we figured out book binding.

So Microsoft are emulating an archaic and impractical form of information presentation and calling it modern, how typically Microsoftian. Unless of course, this is a rare example of Americans using the word 'irony' correctly, in which case, bravo!