Consumer preferences, reduced technology costs and government policies that increase labor costs are driving a trend toward automation in the restaurant business. If you make something more convenient and less expensive, it tends to catch on. As recently as the 1960s, gas-station employees would rush to fill your car’s tank, wash the windows, check the oil and put air in the tires. Telephone operators made your long-distance calls and bank tellers cashed your checks. Those jobs now are either gone or greatly diminished. Today, we reduce jobs whenever we shop on Amazon instead of our local retail outlet, use an...