Imagine that your local grocery store announced they would start employing several nutritionists, each of whom had years of training to help people improve their diets and health. Excited, you go to the store to get your personalized diet plan. But when you get there, you discover that the nutritionists are all busy filling customers’ carts with food. When you ask if you can talk with a nutritionist to get advice on your diet, one of them says, “We would love to talk to you, but we’re only paid to fill carts with food, not to advise customers on what to eat.”