I think Montresor tells the story to express his pent-up emotions and to make others understand his perspective. It might also be a way for him to relive the moment and show how clever he was in carrying out his plan.
It could be that Montresor wants to show how he was wronged and that his revenge was justified. Or perhaps he just wants to share a dark tale for the shock value.
Maybe he wants to get something off his chest or seek some kind of validation.
Well, it's not explicitly stated. But you can infer that a significant period has elapsed, as Montresor recounts events with a sense of distance and reflection.
As a fan of online literature, I don't have the ability to directly access the rating system of You Fei or the feedback from the audience, so I can't understand why the audience gave it a score of 1. However, according to my understanding of the online literature industry, the audience's ratings can be affected by many factors, such as the storyline, character creation, writing style, plot twists, plot settings, and so on. If You Fei did have some problems, such as unreasonable plot, inadequate character description, poor writing, etc., then it was understandable that the audience gave it a low rating. However, if the audience's low ratings were only because the plot was too Mary Sue or the writing was too naive, then it was likely that it was a matter of personal taste and aesthetic views of some readers. In short, the audience rating was a subjective matter that required a comprehensive consideration of many factors. No matter what the rating is, we should look at this work objectively and not draw conclusions just because of some objective indicators.
Perhaps the intended audience is the general public interested in science and the story of great scientific minds. Darwin's story is so fundamental to our understanding of life that many people would be interested in hearing it from his perspective.
Well, it could be someone close to him, like a confidant or a friend.
One possibility is that he could be telling his story to a priest. In the context of seeking absolution, Montresor might be confessing his dark deed. Priests are often the recipients of confessions, and Montresor, burdened by his conscience perhaps, could be unburdening himself to a man of God.
It could be to a close friend or confidant, someone he trusts to listen and understand.
It could be for young adults who can relate to his experiences in school and growing up.
He could be confessing to a priest. In many literary works, a character might confess their sins to a religious figure. Montresor's act was a heinous crime, and confessing to a priest would be a traditional way to seek absolution, though there's no clear indication in the story that it's a priest.
It could be for his followers, to strengthen their faith and understanding of his life and teachings.