A TOGOM story is not the same thing as a deathfic, and a woman who grieves for her living child as much as she grieves for her dead child has simply got her priorities wrong.
I think there's a huge hole in your theory.
Lois stopped grieving after she discovered that Clark was still alive. The fact that he was still alive didn't lessen her grief at all when she *didn't know* that. When she found out he was still alive, she was overjoyed. She didn't spend the rest of the series (or her life) mourning him because she once thought he was dead.
You're correct in saying that a TOGOM story is not the same thing as a deathfic. One explores grief that ends up having a happy ending, because Clark is not dead. Just like 'Don't Tug On Superman's Cape' has a happy ending because LOIS is not dead (as Clark had briefly thought). To the best of my recollection, he didn't spend the rest of the series mourning her almost-death either.
In a true deathfic, yes, the character is dead. But I'd rather think that those stories are written as a way of showing how we cope with such a huge loss, not as a way to wallow in the grief.
