It's wrong to be proud of not tipping.
Grant rides in a cab, makes it to his home and leaves without tipping.
Grant wants to talk to his family about the cab.
Grant talks to his family, and he was ashamed that he had no money for a tip.
Grant brags to his family that he didn't tip and paid only the fair.
Grant's family conforts him and tells him that he should be happy to have made it home at all.
His family is upset but Grant kept talking about bringing the tipping system down.