If you've heard of fanfiction, you're probably aware of the negative connotations that come with it. Fanfiction, or fiction written by fans of a TV show, book, or any other original creation, is often associated with unpolished writing and out-of-character shenanigans. It's not uncommon to hear people laugh about how all fanfic writers are prepubescent kids too wrapped up in fake ships (relationships in the fandom) and unrealistic fantasies. Some people even characterize fanfiction as a form of plagiarism, since the writers essentially use a fandom's pre-existing characters in a different plot.
While many stories are, indeed, in need of serious editing, a lot of fanfic is highly sophisticated. Some writers are able to capture the characters in their chosen fandom so completely that the story seems authentic to the universe it's written in. It's hard for me to dismiss these writers as uninspired copycats because their writing clearly shows that they have a firm grip on characterization and plot. My own attempts at writing fanfic have convinced me that proper characterization in fanfic is often harder than creating original characters. Fanfic writers don't have as much freedom to make characters perform certain actions, as they must constantly think about whether the characters are authentic to the original work.
On the flip side, some writers diverge so much from the original work that they essentially create a plot and characters of their own. Many famous authors got their start in fanfiction, including Cassandra Clare (best known for "The Mortal Instruments" series), Meg Cabot (best known for "The Princess Diaries" series), and S.E. Hinton (best known for "The Outsiders"). But when readers hear that these authors have written fanfiction, many of them assume that their stories are unoriginal or retrospectively look at their writing more critically. Suddenly, every questionable plot device or flawed characterization is reflective of the authors' origins in fanfiction, despite the fact that accomplished authors who haven't written fanfiction make those same mistakes.
The assumption that fanfiction writers can only create derivative work, even in their original stories, is especially true for the creation of characters. When I tell people that a certain author has written fanfiction, they'll often start looking for similarities between the author's original characters and characters in the author's fandom. While this author's characters may have begun in fanfiction, they've diverged so much that they're not the same characters anymore. If most people can accept that original characters change drastically from their inception, why are characters born from fanfiction seen as unoriginal when they've changed just as dramatically?Just like in any creative form, there are good and bad sides to fanfiction. A lot of fanfiction is flawed, whether the story has bad grammar, Mary-Sues (unrealistic characters that lack flaws), or gaping plot holes. But at the end of the day, it's important to remember to push past the prevailing narrative that certain art forms are more legitimate than others, simply because they're more mainstream.