Ok this is just a guess but how about in the days when we still thought the Earth was flat, most of the developed (map drawing) countries were in the northern hemisphire and so would naturaly asume they were on the top of a flat world, or they would fall off ! and as our knowledge of the planet grew the flat maps of the north devoloped into the globe we have today. Or maybe it just made sence to draw a map facing the direction that a compass pointed.
By the way you can get road maps that read south to north so you dont have to read place names or follow roads upside down if you are traveling north, designed for woman drivers I think!