The setting influences the story’s point of view because
Setting is where and when a story takes place. The important thing to remember is that the setting encompasses the local customs and traditions. We are who we are because of the setting we in, and our behavior can be influenced by the setting too. In this case, the fact that the narrator is Italian has a great influence on his behavior and how he views himself.
Few Italians have the true virtuoso spirit. For the most part their enthusiasm is adopted to suit the time and opportunity, to practise imposture upon the British and Austrian millionaires.
This influences not only the narrator's attitudes, but his attitude toward Fortunado. Montresor, the narrator, describes his “friend” Fortunado as a “quack” in most things. The importance of being a gentleman in this society is one of the reasons that Montresor is able to convince Fortunado to go down into the catacombs with him. Another reason is the time of year.
It was about dusk, one evening during the supreme madness of the carnival season, that I encountered my friend.
The carnival made Fortunado more friendly and more susceptible to influence. The general drunkenness and friendliness, as well as the gentleman's code, allows Montresor to take advantage of Fortunado and get his revenge.