LabRat, perhaps this is due to the fact that if characters are killed on TV, they're gone and usually don't come back (unless they're named Buffy, Daniel or Lex, or happen to be part of a soap opera cast). If a character gets killed in fanfic, another writer, or even the same writer, can still use them in a new fic where they're alive and well smile . It's not so final and it's not 'official.'

Fanfic | MVs

Clark: "Lois? She's bossy. She's stuck up, she's rude... I can't stand her."
Lana: "The best ones always start that way."

"And you already know. Yeah, you already know how this will end." - DeVotchKa