Shouldn't I be concerned for Nineveh, that great city, in which are more than one hundred twenty thousand persons who can't discern between their right hand and their left hand; and also much cattle?"
As to the reason why Jonah had two graves, we pray that we may be indulged in a little speculation.  Jonah, after converting the largest pagan city in the world would ever afterward have been persona "non grata" in Israel, Jonah's wish to die probably being connected with this certain rejection in Israel.  Our basis for this opinion is simply that this was surely the reaction of Israel in the case of the apostle Paul, another Jew, who converted many Gentiles.  There is absolutely no reason whatever for supposing that their attitude toward Jonah would have been any different than it was toward Paul; and, if we may believe some of the traditions that have come down to us regarding Paul, how even his wife deserted him, how the hierarchy had a public funeral for him, disowned him for ever, and hounded him to the ends of the earth with the avowed purpose of murdering him - if any of this is true (and certainly, some of it is true, being related in the New Testament), it is not hard to believe that Jonah would likewise have suffered the undying hatred and animosity of his own people.