While I think there is plenty of historical and societal evidence to support some of Ann's beliefs I tend not to give it much credence in regards to our fandom and the fics that are written.
To me the most telling factor in any 'deathfic' (a term I despise) is not who dies, but who lives. As Pam pointed out, most of the writers in this fandom who would venture a go at such a storyline are more interested in examining Clark's angst, therefore someone Clark loves would, by default, have to be the one to go. And Clark loves no one more than Lois.
Even given my 'reputation' I can only remember couple of fics where I included a non-phoenix death. In one, Clark had died on New Krypton and Lois was confronted with the idea of impregnating herself in order to raise a child of Clark's. And in the other, Clark dies on New Krypton and Lois dies because of a dangerous investigation. They were reunited spiritually in the end. (Yeah, hokey I know, but it seemed like the thing to do at the time. Besides, it was Lois' wish being granted.)
Death can be a useful tool in a story to bring about the most extreme emotions in another character. And, again, the victim is usually chosen to allow the reader to experience these extreme emotions of the lead of choice, be he he or she she. Unfortunately, such plot points seldom lead to happy endings, and lets face it happy endings are the preferred outcome in this fandom.
Tank (who points out that both Wonder Woman and Supergirl have died in the comics and both got better)
