What the discussions lacked was focus. I see lack of focus a lot in student work. It starts off well, with an engaging character or interesting situation but then the story drifts off elsewhere. This is fine if you're, for example, John Irvine and are known for writing long discursive and digressive novels, but not so good if you're aiming for a 1000 word short story.
The reader is left puzzled and uncertain where to look. Who is the main character? The person we started with, or the person who seems to have taken over the story? Is our setting here, or there? Is the story about X or Y? The reader wants to engage, but they don't know what to engage with.
Short stories should be about one thing, one person. Nadine Gordimer describes them as a single, beautiful pendant hanging from a chain, whereas a novel is a string of beads interwoven to make a beautiful whole. Both require focus to make them work, so when you're writing, don't let yourself get sidetracked. Know what you're writing about, then write it.