I keep my stories up because 1) people seem to still like them, and I hate it when my own favorite stories are deleted; and 2) it's a massive stroke to my massive ego when I get a good (or bad, really) review for something I wrote AGES ago.
I don't write fanfic anymore. I'm really only on lj. But cheers if you've stumbled on this account.
Keep calm and carry on, guys.