Lots of interesting numbers and anecdotes in the piece, but they fail to mention a simple explanation for why tipping still exists despite being discriminatory

Lots of interesting numbers and anecdotes in the piece, but they fail to mention a simple explanation for why tipping still exists despite being discriminatory and inefficient: we're playing an asymmetric game. - Tipping is massively beneficial to both restauranteurs (who can pass on the cost of human resources to the customer) and to servers (who can make a good salary performing unskilled labor - provided they are good looking, well spoken, etc etc). - To the rest of us, it's not so terrible that we are willing to bear the public shaming we could be subject to for failing to conform.