"There are a lot of people nowadays who are totally ignorant of history. This kind of "literature" is their only source of history. As a result of this book, there are lots of people out there who think that the Salem witches were in fact witches and deserved to die."

That is the reader's fault, not the author's.

"I see no idea why subsequent editions shouldn't include a large disclaimer that none of the stuff in it is true."

Because fiction is, by definition, NOT factual, even if it's based on a historical figure.

"In contrast, there's another book called Heretic's Daughter which although historical fiction, is excruciatingly true to the facts."

Sorry but historical fiction does not always have to meet your personal standards of factual information. Nor should it require some kind of disclaimer for the morons who don't understand the definition of "fiction". It's lawyers like you who have created the usage of all those moronic warning labels for consumer products. This is the same thing: requiring a warning or disclaimer to explain the blatantly obvious to the idiots of the world. Whatever happened to good old common sense? No, no, we must cater to and encourage the lack of it.

You're just having a knee jerk reaction because you feel personally involved in this, being a descendent of Deliverance Dane's relatives. But did you know Deliverance, personally? I've never seen the point in forming personal attachments to someone I never knew by multiple generations. While misinformation is frustrating, to say it's "hurtful" to you personally is really stretching it.