This problem is discussed a little on this entry in the Wayward blog. http://www.unlok.ca/wayward/inspiration-time-world-building/
These are a couple of problems listed on the blog entry:
* Sometimes a map can just be desert or non-desert biomes or very small
* Lack of proper or forced variety.
And this was listed as an eventual goal for the game:
* Have guaranteed environment diversity and biomes. Swamps, tundras, forests, jungles, deserts, etc.