Yeah, i think the reason behind this is because the original team probably spent 85% (speculating) of the budget on the super detailed graphics. It seems like they realized they were going to fall short on creating zone diversity so they just made each map monotone -- either that or they figured the sheer graphical detail would cause ppl to not care about the monotony. The problem with these super fine graphics, as far as spicing up the scenery, is now the current team has to match the high caliber of the graphical detail, otherwise the art won't blend correctly.
I'm sure that even the dungeons took a ridiculous amount of time and money to design. The company probably won't commission any rapid changes to zone art until the game has been p2p for a long time. Sustaining the graphical detail is like trying to commute in a hummer, on a 45k/year salary.
