Some of San Francisco's robot-run restaurants are failing. It could simply be that we still want to be served by humans, not machines.

· A trend in food automation has swept the country in recent years.
· The San Francisco Bay Area has seen a high concentration of robot-run restaurants, but some of them have failed.
· It may simply be that people still value some sort of human interaction in a dining experience.
· Here's what it was like visiting some of...