I'll try to explain. Imagine you and a friend come up to a bartender, you both order some beer. You offer to pay the total amount out of kindness. Your friend also wants to show the same kindness and they offer to pay. You go back and forth because you both want to beat the other in kindness. Whoever wins the argument pays. Same idea here. It's not "moronic" or illogical, it's just culture. You don't have to agree with it, but calling it names is more moronic than the act itself