This is why they're so hard for us writers to write. Of course, there are two kinds of stories: plot-driven stories and character-driven stories. In plot-driven stories, the characters are more of an afterthought. Still important, of course, but in plot-driven stories, the plot is the most important feature. Think Harry Potter. In character-driven stories, the plot is more of an afterthought with the development of the character centerstage. Think Catcher in the Rye for this one. I've written both kinds of stories in both novel and short story form.
Surprisingly, characters in plot-driven stories are more difficult to develop. In character-driven stories, they usually just spring up fully-formed. But in plot-driven stories, I have to work harder to think them up or at least to find them. But even though plot is the driving element in plot-driven stories, characters are still incredibly important.
In plot-driven stories, characters are the ones to essentially drive the plot. A character's narration can even change how the reader perceives the events in the plot. Maybe plot is the number one reason people keep reading, but good characters are essentially what make them stay. Good characters accentuate a plot and a story.
Plus, readers are total suckers for characters they like. Those important characters are the reason why they remember a book. And that's what you need to live for as a writer.