Comment 8 for bug 1465331

Besides the lack of a design decision, there's a very practical reason why Dash doesn't rotate at the moment: it's slow as hell to relayout itself when its window gets resized. So it's better to not have a feature than to have a badly done one. That's specially true for the tablet where a rotating dash makes all the sense.

Sure this performance issue must be fixed, but it hasn't been a priority so far.