Why didn't Luffy kick Nami out of the straw hat group?

Nami, who has always been a drag, why didn't Luffy kick her out of the straw hat group?

Nami, who is not as calm and incompetent as Robin in danger, can always stay in the straw hat regiment!

Is there more affection between Nami and Luffy?

Luffy's straw hat: Analyzing Lu Na in Oda's works, there is a strong evidence that Luffy's straw hat is. However, before we begin, we must understand the significance of straw hat to Luffy: "The moment we lose our fate with the hat is when we become one, or when we die." Yes, everyone who loves One Piece knows the importance of straw hat to Luffy, because that is his agreement with red-haired Jack.