But...
Jack was not willing to risk Rose ending up in the water where she would more than likely freeze, and he bravely stayed in the water, and ultimately met his death. While it is unfair that Jack died when he clearly did not have to, the fact is that James Cameron explained it best when he said that the death of Jack helped Rose become the person she was always meant to be. Though it is sad that Jack died, the two of them were ultimately reunited in death, and would spend the rest of eternity together…