A story idea may be horrific, but it still allows a writer the chance to practice the art. At some point, a good idea and good writing will need to meet to give a story a decent chance at publication, but while the writing is still in the formative years, any idea, even a bad idea, will work.
In high school, I worked on a novel-length science-fiction story titled “The Key”. Sounds fantastic already, doesn’t it? The key to what? It’s so intriguing.
In the story, the protagonist (I don’t remember his name) works at a cryogenic lab (highly original, I know), freezing people who are dying of incurable diseases. Ironically, the protagonist himself ends up with an incurable disease (no way anyone would see that coming). So he volunteers to join the group of frozen people in hopes that someone will find a cure one day.
The protagonist awakens in the distant future; the United States is in a prolonged war with Canada and robotic spheres hunt people. Not only that, but he soon meets an alien who has escaped to Earth with the technology to open a portal to other worlds (hence where the title comes into play).
Cliché builds upon cliché in this epic failure of a novel that I didn’t even bother to edit (I didn’t understand how to progress through drafts back then). The story is now locked away in the memory of an outdated computer lacking a functional power supply (or some other piece of hardware), but it served the purpose of giving me experience. I worked on dialog, setting, characters and point of view. The fact that the ideas within the novel were horrific didn’t matter because I spent time writing.
I would encourage writers to work with whatever ideas come to mind while learning how to write. It may be fan fiction. It may be clichéd. It may be the worst idea in the world. But if it leads to words on a page and helps with learning the process of writing, it’s worth using for experience. Just don’t try to sell it.