To me, fanfic is fine as an exercise in learning the craft, or shared with a very small group of people. But when it is posted online, it's been published and the potential for the audience is larger.

I guess I look at it this way. If I write a completely original story, print it out, and show a couple of friends, I can still sell first rights. If I post it on my public LJ, I can't.

Now, the Star Trek and Star Wars novels, I don't really consider fanfic, not because the authors are paid, but because they have the permission of the creator, or estate, to publish their work.

Hobb did the work to create her world and characters, and if she doesn't want someone else appropriating them, that is her right. As for her tone, to her it's stealing, and I get mad when someone steals my pen.