They're not very valuable lands. In fact, in Biblical times, it was the spot where evil spirits and thieves could be found. Definitely not places chosen as vacation spots. Yet they have certain things in common which, for all their harshness, can prove valuable. Nature at its most basic, unaltered for centuries.
Deserts are lonely, empty-seeming places.
Israel found God in the Wilderness of Wandering. Elijah found God in the small whispering on the mountain in the midst of the desert. John found the start of his mission in the wilderness. And, through those trials, we are each called to say yes or no to God. Maybe we don't here the call from a burning bush or amidst stones we wish were bread, but we are called, constantly and patiently, through our entire journey of life.