Yeah, but people (defalcon? unsure.) have made other levels using those tilesets.
A good tileset uses a combination. One of my favorite Disguise tilesets is Nature's Ruins because it does this just so well. The ground types are very simple and easy to fit together, but the tileset also has a lot of enormous structures that can only be used in one way, and enormous structures are awesome to look at. Inferno is a good example of going a little too far with style, as half the tiles can only be used with five specific other ones right next door.