I figure they would just be taking up room on her site that would be better devoted to other people's stories. My stories are all on the archive, so why make extra work for A and El?
I think you'll probably find, Laura, that the same holds true for most of the authors who have gfic stories archived at Annesplace. Certainly mine are uploaded to both sites. And I'm sure Annette would be more than happy to include yours and certainly wouldn't think it was wasting her time.
I don't know about anyone else, but I've always just been of the mind that you can't archive your stories too many places. There may be people who find your stories on Anneplace who don't know the Archive exists. And vice versa. It could be a backup. If something happens - heaven forbid <G> - to either site, you still have your stories safely out there.
LabRat