Weirdness isn't the issue. It would be literally much harder to see the bottom side (which is where most cities and humans are located, as you mention) unless you make the globes easy enough to lift, or tall enough to go above most people's heads. I fail to see how that would be better UI.
It would be a deliberately weird design choice to make a globe (which is almost always viewed from above) with the northern hemisphere n bottom.
[1] https://en.wikipedia.org/wiki/Northern_Hemisphere