I think flavourful names do a few nice things:
They're cooler, which is more memorable
They highlight potentially important places in history (depending what we choose), which fits the historical vibe of the game.
They make 0 A.D. less like a generic RTS.
Contrast 'Arabia' on AoE 2 with 'Highlands' on AoE 1, despite it effectively nowadays having different biomes. Some names are more generic, I'll admit, but I don't see the harm in giving them cooler names.
(Not that this is the thread topic...)