Do you think it was creative writing that caused God to have concern for Ninevah? Did He send Jonah to preach because of that concern or in an effort to support His creative writing? Did He express what was driving His decision about Ninevah just so we would know He really didn’t mean it?
I take His concern for those people to be real.
It, of course, aligns with “God so loved the world...”
Now that we have that out of the way let's look at the other side of the coin, man doesn't love God. God told Jonah to head to Niveveh to preach the gospel. Both Jonah and God knew what the outcome would be and Jonah didn't want to do it. Why? Because he knew that Nineveh would repent and God would stay His hand. It isn't that there was a massive revival in Nineveh. They didn't all become Hebrews. It's that they stopped their sinning at least for a little while. And God, in His loving and merciful way stayed His hands of judgment. And, poor Jonah, threw up his hands and said, "Oh brother, as if I didn't see that coming. I hope there was some purpose for me being in that fish for three days."
You want to put all the responsibility on God. God is love and long suffereing. But sorry-it's not a "God issue". You better look at the other side of the coin.