>>90089303Real answer: Because it's an easy way to go vaguely "middle eastern" or vaguely "north African" with less risk of offending someone or getting -too- political; and because in some cases, it allows you to shape a region as belonging to a specific hero or villain, in the vein of Doom's Latveria, Batman's Gotham, or BP's Wakanda.
Lore-friendly answer: Because DC's Earth is canonically, physically larger than the real-life Earth.