I do wonder if early world explorers had been from the southern hemisphere and a tradition of "south up" was already established, if it would still look better to us to have more land on top.

> I do wonder if early world explorers had been from the southern hemisphere and a tradition of "south up" was already established, if it would still look better to us to have more land on top.

No, the preference is conventional.

I should note, though, that Chinese maps were traditionally south-up. There's no reason to expect what hemisphere people are from to control that decision.

(Not only did the Chinese come from the northern hemisphere - they had an official orthodoxy holding that the north of China, where they originated, was morally superior to the south!

Nevertheless, they drew their maps with south at the top and referred to compasses as "south-pointing needles".)

I think the convention was born by magnetic north. I suppose it might also point to non magnetic south. Maybe a combination of the explorers and compass convention.

I suppose we can ask Australians and the kiwis.