You can read a dozen different textbooks or how-to manuals that will tell you the basic rules of what makes a story - a beginning, a middle, and an end.
It's all about who's where on the food chain. When I'm the story editor, I expect my writers to follow my vision. When I'm working for another editor, I'm obliged to follow their vision.
If a story isn't working, I'm simply unable to finish it. That's what usually tells me something is wrong.
What makes a story is how well it manages to connect with the reader, the visceral effect it has.
Were there stories I wrote along the way that were terrible clinkers? God, yes. But they were all a product of their time, and I did the best I could.
Sometimes you're not even sure which of your stories were failures. There are things I've written that I thought were complete catastrophes when I finished with them that have gone on to generate some of my most positive feedback.