I would guess that the particular room is going to be used more as an office/craft room (i.e. something other than a bedroom). I've seen lots of homes where they just build in a desk, or put other shelving in. I have been watching "Clean Sweep" of late (and taking notes), and many of their episodes have the designer putting drapes where closet doors were. I'd rather have the mirrored slider doors--makes the room look bigger and reflects light.
I hate bi-folds--too easy for little ones (and grown-ups) to pinch fingers in, and depending upon the room, you lose a foot or so of space that you could put a bookcase in, for example. But that's me.
Come to think of it, one could also put an entertainment center in that space also, if the wiring were done correctly.