Jonah is not about a prophet running from God, a city with 120,000 people or a big fish with acid reflux syndrome. This small book is a juxtaposition of behaviors with an ironic twist, of the behavior of God's people against the behavior of those who don't know God. Jonah is a condemnation of the ungodliness of God's people.
We all know the story well enough but lets ask "Why?" For example:
In Jonah we see the ungodly (the sailors and Ninevites) behaving the way we would expect Jonah and Israel to behave; responding to God's will. Counterpunctually, we see the Godly (Jonah) behaving the way we would expect the ungodly to; rejecting God's will. How can this happen? I believe that Jonah unconsciously deified programs, statement's of faith, personal creeds and other important points of his Godly identity and justify their shortfalls with a misunderstanding of God's grace and love. In the same sense, we do the same as Jonah.
A wealthy church considered feeding the homeless and poor. After a lot of discussion, the ministry was abandon because it was said the church could not afford the insurance for the every day use of the kitchen. What is hidden in this story is the fact the Church had a secret sacred cow; no one said it but it was understood that financial responsibility was more important than the poor that Jesus' command the church to care for. Shortly after, the couple that initiated the discussion left the church, went down the street and started the same ministry through another church; a church considered to be less spiritual. So how do you think our "spiritual" brothers and sisters responded? They criticized the success of the ministry and the growth of the church. In so doing, they proclaimed that Jonah lives.