Many of the reviews of Stephen King's short story collection, Just After Sunset, have referred to King's introduction to the collection, which talks about when he was first starting out as a writer and wrote short stories, how he got away from writing them, and how editing The Best American Short Stories 2007 reawakened his interest in the form.
It's interesting to see how King's own summation has framed much of the discussion of his work. Many reviewers don't know how to talk about a short story collection as a whole. So, in a sense, an introduction can make a collection more reviewer friendly.
Still, most of the short story collections that I read don't have introductions. And those that do, tend to veer toward a genre, such as science/speculative fiction, horror/suspense, or mystery/crime. In some cases, a prominent writer in that genre will introduce another writer's collection, for instance George Pelecanos introduces Laura Lippman's Hardly Knew Her. (My intention is not to disparage so-called genres but to make a factual observation.)
In so-called literary short fiction, authors will sometimes introduce their own selected or collected works. For instance, Tobias Wolff opens Our Story Begins with "A Note from the Author" that addresses the question of whether or not an author should revisit (i.e. tinker with) earlier stories when putting together selected stories. (Notice he doesn't call it an "Introduction.") Wolff did, in fact, revisit earlier stories--and that's the sole focus of his brief note. And, like King's introduction, it has helped frame reviewers' discussion of his book.
Of course, ultimately, stories have to speak for themselves. And anyone who doesn't want an introduction can skip it. In addition, a popular writer like King often has a very public, ongoing relationship with his readers, who are likely to appreciate insight into his creative process. Truth is, you could ask why more writers don't share their back story and their insights with their readers.
Still, call me a traditionalist, but I generally like short story collections better without introductions. How do you feel about it?