The practice of tipping in the United States give customers the opportunity to be stingy and to take their poor dining experience out of the server. Multiple factors could contribute to someone having a poor dining experience such as the kitchen messing up the food or the environment being too loud. The restaurant owner may lose money indirectly because a customer might not return, but a bad experience will have an immediate impact on the server. So a server never has a set amount they will make in a day which makes it difficult to plan expenses.
An alternative to tipping would be shifting to a model where labor costs are built into food and drink prices. This shifts risk away from servers by eliminating uncertainty and by providing more stability in a servers pay. This also makes it easier for the diner to not have to worry about calculating tip after meals.