Because your inn is short of food. Every guest has different tastes. If there is more food in your inn and guests have more choices, you will order more food and earn more money. On the contrary, especially at the beginning, there was very little food in the inn, and some guests kept sitting there because they couldn't find suitable food. Therefore, when choosing a menu, we should pay attention to each kind of food (rice, vegetables, soup) and each grade (1, 2, 3, 4).