@mcepl Jane Austen's Pride and Prejudice is in the Public Domain, so of course anyone is free to reuse/build upon/create a derivative of the original material; and yes, they can make a profit from their work based on a Public Domain work.
The question is this: is it still fan fiction when they can do anything and everything they want because the work is in the Public Domain?
When is a literary work a fan fiction?
If a producer creates their own derivative of a Public Domain work into a TV series or a film, is it fan fiction?
If that TV series or film is not considered as fan fiction, then why are the works of other authors labelled as fan fiction?
Or say, an author was able to publish their derivative work, sold print copies of it. Since that work is based on someone else's work, is it fan fiction or not?
If it is fan fiction, then you're saying that any work that was not written by the original author is fan fiction?
It means that, all the Star Trek books and productions which were not made/written by Gene Roddenberry, are fanfics?