There is a certain appeal to the idea of writing a short story.
Unlike a novel, writing a short story promises a relatively quick writing process. In many cases, a writer can write the entire story in a day. Editing is less daunting, because the story is short and there aren't as many pieces of the plot to worry about in terms of consistency.
So why do many writers avoid them?
Writing a short story is not easy, it is a completely different exercise than writing a novel. If you're trying to stick to the confines of keeping your story under 5,000 words, you can't waste words, add superfluous details, or develop sub-plots and minor characters. You can put some of those elements in a short story, but they have to be carefully chosen and they have to advance the main story.
A Single Theme or Event
If you are anything like I am, an idea is rarely limited to one specific central theme or element. It rarely involves in a very small set of characters, and there are multiple scenes that you envision to take your main character through their journey. Short stories do not lend themselves well to this, and many writers struggle trying to whittle down an idea into one highly-focused piece of writing. There can be a feeling that you're "wasting" a great idea on a short story, the idea is too good to try to cram into 4,000 words, it needs room to breathe.
The best short stories I've read always seem to focus on a single event, or a single theme. Usually they involve three or four central characters at most. It's really hard for a lot of writers to boil down a story idea to such a small scale.
Let's say you come up with an idea for a space opera, where people with laser swords battle each other, and there's some mysterious energy that flows throughout the universe that only certain people can access. That's a pretty grand idea (I think it might have already been done before). It's too much for a short story. In the context of that idea, a short story would focus on a single day's action, or even just a part of that day. For instance, the short story would be the protagonist trying to lift a rock using the mysterious energy. It can contain some details about this strange "force", but the narrative is about whether the main character can lift the rock or not. Then it's over.
At this point, you're probably thinking that there is a lot more narrative to this story, and you'd be right. But it doesn't belong in this single short story about telekinetic landscaping. There is no rule that says short stories cannot be episodic, you can write them into a story arc, where a small collection of stories form a larger narrative. (I would actually suggest that as a practice exercise: taking a larger idea and breaking it into episodes.)
Distilling a big idea into something smaller can be very difficult. Sometimes less can be more. Short stories allow you to pack a punch. There are no weak spots in the story, or room to write paragraphs or chapters of exposition. The result can be a much stronger piece of fiction than it would have been as a novel. It's hard for writers to let go of a huge idea in favor of a smaller one, but it can be worthwhile.
Next time, I'll explore the thorny issue of what details to include or exclude in a short story.