Ever heard of The Cricket on the Hearth? It's one of the Christmas books that Charles Dickens wrote following the success of A Christmas Carol. The story is sentimental and features a cricket who acts as a guardian angel and a miser who is transformed by the Christmas season. The novella is divided into "chirps" instead of chapters. Although commercially successful at the time, the story receives little attention from critics today. Most commentators, I suspect, would call it a minor work if they bother to mention it.
Critics often refer to some story or novel in a writer's oeuvre as a minor work. I assume the critic means that the work in question has flaws in execution or concept that render it less satisfying than the author's major works. The minor work is not as important. So minor is a relative term to distinguish great works from less-than-great works. Or maybe it's a nice way of saying this one sucks. Or maybe the ideas presented in the story are no longer relevant to or popular among critics.
From a critic's perspective, it makes sense to distinguish minor and major works. But from a writer's perspective, the idea seems odd. Looking back over my stories, I can admit that some are less successful than others and I can learn from the "failures" maybe more than from the shining successes. However, I never think of any story as a "minor work" while I'm writing it, even if I know the concept is less ambitous. I don't care less about the characters or put less thought into the descriptions of time and place. Orson Scott Card writes in How to Write Science Fiction and Fantasy that a writer must simultaneously believe:
1. The story I am now working on is the greatest work of genius ever written in English.
2. The story I am now working on is worthless drivel (p. 109).
In other words, you have to have enough confidence to send it out and be ruthless enough to edit it. If you think you're writing a minor story, will you ever believe it's worth the risk to submit it? In fact, if you think you're writing a minor story, you should stop working on it. Move on to something else, because it will certainly never rise above minor status and most likely won't rise to any status at all. I suspect that when Dickens finished The Cricket on the Hearth, he thought it the best Christmas story ever written.