I'm not sure what it is with kids and fiction, but my students are writing short stories right now, and they couldn't be happier. Composing fiction is not mentioned specifically in either my state writing standards or in the draft of the new National Standards that was released today, although both include objectives addressing kids writing narratives, and of course that includes fiction.
I've found that many middle school teachers hesitate to include fiction assignments in their writing programs; I used to be one of them. I guess it didn't seem quite rigorous enough to me, either that or it could be that such assignments usually produced such sprawling tales teeming with ill-defined characters who wandered about without ever resolving anything that I had no idea what to do with them.
In her foreword to Ted DeMille's book, Making Believe on Paper, Nancie Atwell recounts a conversation she had with the educational researcher Nancy Martin on this very topic. Like many of us, Atwell was explaining why she didn't teach fiction, despite the fact that it is what most kids love to read best. She considered her students' fiction "daydreams on paper."
But Atwell tells how Nancy Martin convinced her otherwise. In Martin's opinion, fiction gives young writers the chance to compose fluently and at length. Martin also makes the point that fiction "gives children access to the hypothetical" so that "they can begin to see how to improvise on their own experiences." She understood children's stories to be fables where they reimagine their lives and mix them with the stories they've read or heard.
That is an accurate description of what my students do with their fiction, although they are influenced also by the stories they see on TV and, more and more, in games. Humans have always used storytelling to make meaning of our lives, and I think it's important to give kids the opportunity and the tools to do that. More importantly, though, writing fiction is motivating to my students: with few exceptions, they write cheerfully and at length. For that I'm glad, because I can't teach writing craft, conventions, or skills to someone who won't write.