Moreover, there is no obvious reasons for why this should be so. Usually the person who dies in the deathfics does so for completely random reasons.
There's the one flaw to your logic (to my way of thinking, at least). Lois can die for completely random reasons. She's
vulnerable in ways that Clark isn't. You have to work at it to kill off Clark. You have to drag in a villain, supply them with Kryptonite, trick Clark into showing up... If the fic is about emotions (which I think most deathfics are - the character dies for a *reason*, which is usually to explore the emotions that arise from that death), then it's sometimes not worth all the other hoops you'd have to jump through.
Plus, like someone else suggested, maybe it's because the majority of the audience here is female and we appreciate seeing the tributes to Lois as woman and her place in Clark's life and heart. She has definite value in the eyes of this group and this is just one of the ways to explore that.
ETA:
But will the other members of that fandom appreciate her tenacity?
I can certainly respect your opinion and views. But I marvel at your tenacity.
