Humans know when it's not a good story. Unless you do this for a living, you may not know exactly why you don't like a story, but you can't fool an audience ever. They know when you have it and they know when you don't.
It’s a miserable story!” said Bruno. “It begins miserably, and it ends miserablier. I think I shall cry. Sylvie, please lend me your handkerchief.” “I haven’t got it with me,” Sylvie whispered. “Then I won’t cry,” said Bruno manfully.
Detection is, or ought to be, an exact science and should be treated in the same cold and unemotional manner. You have attempted to tinge it with romanticism, which produces much the same effect as if you worked a love-story ... Some facts should be suppressed, or, at least, a just sense of proportion should be observed in treating them. The only point in the case which deserved mention was the curious analytical reasoning from effects to causes, by which I succeeded in unravelling it.'' —Sherlock Holmes on John Watson's "pamphlet", "A Study in Scarlet".
I try to turn a written thing, when I'm in trouble with it, into a spoken thing: I start imagining what I would say to someone if I were trying to tell the story or make the argument.
A love affair is like a short story--it has a beginning, a middle, and an end. The beginning was easy, the middle might drag, invaded by commonplace, but the end, instead of being decisive and well knit with that element of revelatory surprise as a well-written story should be, it usually dissipated in a succession of messy and humiliating anticlimaxes.