The engine itself is not good enough for such high system reqs. Some of the graphics are really ugly. Trade posts and rivers for example. Compare it to a game with similar system reqs - BF3. Even in Alpha it looks great in DX9. Most people run it on PC with Civ5 recommended settings.
If Civ5 had moving vegetation, wind, birds and day-night cycle...
If Civ5 had moving vegetation, wind, birds and day-night cycle...