Have you ever seen a globe? They are always tilted so you can easily view countries below the equator.

Besides, 90% of the world population lives above the equator, so if there is a slight bias towards making the northern hemisphere more easily viewable, that's entirely justifiable. That includes 1.4 billion people living in India, another 1.4 billion living in China, etc.

Kids are short. Australians turn maps so they are south side up anyway.