(“Intermittent” meaning, “I’ll deal with them as I think of them.”)
We will assume, for the moment, that you don’t want your readers disgruntled; that you want to keep them pleased with your work so that they will, you hope, keep wanting more of it. I will grant that there are writers whose goal, at least for a particular piece of writing, is something other than pleasing the reader — the desired effect may be a justifiable anger at the system, or a fuller understanding of the futility of it, or something else along that line — but for the purposes of this blog I’m assuming a less rarefied, but more common, goal.
One of the primary causes of reader disgruntlement is simply this: The reader feels that the author has not fulfilled the implied promises he or she made at the start of the story.
For an example, let us consider a popular novel in the romance genre. I’m using romance as an example not because I have anything against romance novels — far from it; I read them even though I don’t have the knack of writing them — but because a typical romance novel is as formal in its structure as a sonnet. There will be A Heroine; there will be A Hero; the primary action of the novel will involve their relationship, its Trials and Misunderstandings and Ultimate Consummation (with all-out steamy sex or with a single significant kiss, depending upon the overall hotness level of the text); and there will be a Happily Ever After. A story that lacks one of these things may be a failed romance novel, or it may be something that only looks on the surface like a romance novel — but readers who picked it up and read it in the understanding that what they were getting actually was a romance novel are not going to be pleased.
They will, in fact, be severely disgruntled.
It’s possible, of course, that the author of the story intended to subvert the romance paradigm in exactly that manner — but the intended audience in that case is not the community of romance readers, but the community of readers who derive pleasure from subverted or inverted or otherwise tinkered-with paradigms. (Who can get just as disgruntled if they’re promised a subversive experience and don’t actually get one.) Someone who’s been promised a steak doesn’t want artfully manipulated tofu, any more than a committed vegetarian wants to be slipped a piece of meat unawares.
About the only way a writer can get away with not delivering what was, by implication, promised is by giving the reader something even better — and not just any something even better, but the kind of something better than a reader who had his or her mouth set for the original dish is also going to like.
(Nobody ever said this job was going to be easy.)