I understand exactly what you mean about "Wuthering Heights"! I think for me because both Heathcliff and Cathy were very tortured and damaged souls and also because of the circumstances it happens that the way story developed was the only way they could be together. And there is a hint about after-life and there is an incarnation of them in the children's story.

But in the case of "Gone with the Wind" - why their little daughter had to die!! ** very sad ** And totally don't believe Rhett would ever stop loving Scarlett.