The general reason for reducing graphics quality late in a game's development cycle is simply lack of time for optimisation; it's the last resort for getting performance on the recommended hardware up to where it needs to be. I've no doubt the overall graphics quality will improve as we go along, but for the moment we have to put up with yet another side-effect of the game having been launched well before it was fully baked."downgraded" is such a bizarre term to use, it paints a picture of a Dev team that purposely made something worse because they felt it was too good, rubbing their hands together at the thought of stealing all those pixels from us dumb gamers, lol.