No particular reason. In this case, the ceramic would be a part of the beverage container, built-in at time of manufacture. Imagine having mugs that when you pour soda, the beverage self-cools. No ice, no watered-down drink. Or other beverages that stay cool without ice, and self-stir. No batteries or wires to contend with, and can be placed in a dishwasher without harm. I would patent it if I had a working prototype.