It's just the map that I've adopted over time... My favorite reason is that the land up north, around the arctic circle like Alaska, Russia, Scandinavia, and Greenland are all very tall in height and form a basin around the whole world which can "hold" a lot of the water mass of the oceans. The map layout also has a lot of water space that allows you to move the continents around in order to find an accurate depiction of land distances.