I don't know Ms. Gabaldon nor have I ever finished one of her books, but I can tell you straight out that unless she issues an apology to ALL fan-fiction writers, I will never buy another one of her books nor will I ever recommend her to anyone. I understand not wanting people to write fan-fiction about your work. Okay, that's a bit of a lie. As a writer of both fan-fiction and original fiction myself, I don't understand why somebody would be so against something done out of love for the work and characters. If Ms. Gabaldon had simply come out and said, "I don't like fan-fiction. Please do not write it about my work or my characters." I would not have an issue at all. It is perfectly acceptable for somebody to want to keep their toys all to themselves.
My biggest issue is the blatant disrespect and attack on fellow writers -- yes, fan-fiction writers are still writers. I've read fan-fiction that outshone the work it was based on in both the technical writing and the creative world-building.
So, Ms. Gabaldon, I would just like to say -- please think before you type next time because alienating any portion of your fan-base through insults is never a good idea.