This is a much better comparison to make.
-however-
The graphics in Aht Urghan zones were created after years of experience and real world performance results with the graphics engine. The initial FFXI areas like Bastok, and Jeuno are really quite bland when you look at them. This was due in part to the development team playing as conservative as possible with the engine because they had to prepare for worst-case scenarios in hardware (particularly the PS2) and software performance. Because FFXIV is built a new graphics engine, the same precautions had to be taken.
Another factor for the rather lackluster environments might be marketing. It makes more sense to keep the standard for graphics rather low at first so that you can continuously raise the bar and dazzle the players with each new expansion.
Even if what we have now isn't the end all of graphics, it still looks very nice. As time goes on, and new content is released, I have no doubt that we will begin to see some fantastic stuff in this game.