Why aren't there more settings like Maztica and Al Qadim, or more original settings that aren't heavily based on one real-world culture?
The problem with the concept of "fantasy country X" is that if the author and/or the readers are largely ignorant of the place being spoofed, then you have to resort back to big, meaty stereotypes to telegraph what's what.

Maztica is a good example of shallow copying. It's a minimal gloss of the era of the Reconquista, and the authors really don't have a feel for the Mexican Basin beyond human sacrifice, obsidian, and feathers. No Popul Vuh. No visual cues from the Mayan or Aztec codices. No credence to the region's distinct understanding of life and death, of nature or the spirit. There's not even an attempt to make the setting "fantastic" with magic or the supernatural, really...a few critters, "feather magic" (no, really). It's flat.