I really wish someone would add an east-is-up mode, since that's the traditional orientation for maps — and the root of the word 'orientation' to begin with.
Because the sun rises in the east. At least in Indo-European cultures, which were once reliant solely on agriculture and transhumance, the sun was extremely important. Without a compass, it's also extremely convenient, being the easiest celestial body to spot. As such, ancient Indo-Europeans stood facing east when performing religious rites. The reconstructed proto-Indo-European words for "north" and "south" are also the words for "left" and "right" respectively, because the north is to your left when you're facing east, etc.