Jonah is the only one in the parable that that Lord has a problem with. He receives no resistance from nature:  the sea, the winds, the giant fish, the vine that grows then dies, all obey His Word.  He also receives no resistance from the Gentiles: the sailors repent and believe and the entire city of Nineveh, including their king, repents and believes. Only Jonah resists the word of the Lord.  [...]

The parable is about our willingness to serve the Lord in the manner He intended.  And what does He intend? He intends for Jonah, for Israel, for the Church, and for us individually, to live for those around us.  We are embodiments of God's presence in and for the world.