I would disagree! A temple itself can be a masterpiece... think outside the box. On the fly you can change a temple into a dungeon and hop between multiple cave types, you can also add a sense of levels and depth all on 1 map similar to provinces.
I'm going to need a visual representation for this. My indoor maps always look monotonous.
Some of the tilesets, sure, you can use your imagination and provide some amount of depth; But only because what's available allows it, e.g the mine tile sets. How would you apply that to something like the WT tilesets, where we have little more than a corridor to work with?