More than any of that, it's influenced by Mapuzungun in a way other countries just aren't exposed - Argentina's Conquest of the Dessert was more brutal, and is the only other modern country where Mapuche land was.
To desert, v, stress on the second syllable, means to leave/abandon something.
Desert, n, stress on the second syllable, is what you deserve "he got his just deserts"
Dessert, n, stress on the second syllable, is a sweet course of a meal that follows the main course. It has an extra s because of its etymology not its pronunciation.
I'm quite sure this mess was designed to be as confusing as possible.