Jonah's neighbors weren't like him: they looked different, acted differently, and worshipped a different god. Consequently, Jonah could not see in them any capacity for goodness.  In other words, Jonah was racist and prejudicial.

Through the words of pagan sailors, Jonah learned a lesson relevant to believers today: the entire world should expect The Church to seek their welfare.

From the Fray,
-chaplain mesaeh