This was pretty nice. She finally solved her problems and he can move on from his life.
@Randomizer It's because moving on is considered a good thing. People die, it's a natural thing. So to be able to go forward with your life instead of being shackled is a positive.
Her getting to go to the afterlife where she belongs is a good end for her. And him finally being able to let go and move on with his life is good for him.
The idea of these ghosts to begin with is them having regrets and dealing with those regrets. She dealt with her regret and he dealt with his. The idea of a ghost is a metaphor for regrets and getting rid of them.
And what grey area are you talking about???