I just don't see any reason why they need to.
I always respond to this one, Tank, with I don't either.
Need? I doubt it. I need air to breathe, food to eat, but I doubt any author
needs to write nfic. Or fanfic come to that.
OTOH - do you have to need something to enjoy doing it? I don't
need chocolate either, but it's darned good to eat.
So I tend to eat it.
So, I'd conclude - need? Nah. Do it just because it's fun? Sure!
Julie, I think you might find that things are very different in nfic than you imagine them to be and it seems clear to me from reading your posts that you're slightly confusing the porn sites and suchlike with nfic. But that's okay - it's an easy mistake to make when you have no other reference to compare it to, so I don't think you should feel dumb for making it at all!
Back when I first joined the fandom, I assumed nfic was what I knew of it years previously. Then nfic meant slash fic - Kirk and Spock fanfic written by Trek fans in which they had a gay relationship. That wasn't at all to my taste and although I knew that much of it was very well written, I hadn't read much.
Given that, I wasn't interested in reading nfic either
...until one day I accidentally stumbled over Menolly's nfic LNC stories on the net while looking for fanfic and was blown away by the sensual, beautiful, waffy and humourous depiction in her stories of our heroes in love and loving each other. I was amazed. Nfic had sure changed some since my day. I had never imagined nfic was like this! Shortly after that I found other great LNC nfic writers and never looked back.
Now, I'm not at all saying here, "Hey, try it out, you'll love it!" because you may not. It may not be to your taste at all and if you never try it out - that's entirely your choice. Stick with what you like - life's too short for anything else.
I only offer it up as an example of how I too misjudged the genre to begin with. I'm sure others have too. So you're not alone.
LabRat