I don't think he's choosing to die. It says 'when years had passed'. Apparently he lived there alone for several years. There's no reason why he would die now. I've got two theories about why he doesn't go aboard the starship. Either he has some kind of duty as the sole survivor that compels him to stay on the planet, or he doesn't trust the aliens in the starship. After all, he hides from them, suggesting that he couldn't just tell them to leave him alone. On the other hand, the phrase 'haunted savior' seems to suggest the first option. He's the sole survivor; he didn't save anyone else from the disaster, so he probably plays an important role in the greater scheme of things.
I don't think he's choosing to die. It says 'when years had passed'. Apparently he lived there alone for several years. There's no reason why he would die now. I've got two theories about why he doesn't go aboard the starship. Either he has some kind of duty as the sole survivor that compels him to stay on the planet, or he doesn't trust the aliens in the starship. After all, he hides from them, suggesting that he couldn't just tell them to leave him alone. On the other hand, the phrase 'haunted savior' seems to suggest the first option. He's the sole survivor; he didn't save anyone else from the disaster, so he probably plays an important role in the greater scheme of things.