Why do Kino and Juana throw the pearl away?

Kino and Juana return the pearl to the ocean because it no longer holds any value for them. In this, Kino discards a meaningless object. The pearl has no value in the sense that, without Coyotito, the pearl has no power to provide for a better future for Kino and Juana, who could gain only simple material items from their fortune. Kino's repudiation of the pearl is an empty event, for he does not make a meaningful sacrifice. He instead rids himself of an unwanted object that causes him pain. As a parable, The Pearl is an empty one, merely choosing to heap tragedy upon its protagonists and forcing them into pain and agony without offering them an alternate option or any possibility for hope.