The world of the story is one of Magic Realism, where elements of supernatural and outright magic are considered ordinary. Because of this, the discovery of a man with wings is not considered an extraordinary discovery, as it would in the real world, but instead something to be pondered and examined; is the man an angel or simply a man who happens to have wings? The people in the village are used to sideshow exhibits with strange mutations, and it is revealed later that magical curses that can change a person's body are accepted as real and might even be commonplace.
But when they went out into the courtyard with the first light of dawn, they found the whole neighborhood in front of the chicken coop having fun with the angel, without the slightest reverence, tossing him things to eat through the openings in the wire as if weren't a supernatural creature but a circus animal.
(Márquez, "A Very Old Man with Enormous Wings," salvoblue.homestead.com)
This reaction is one that shows how little significance these people have for truly strange or extraordinary things. Far from being awed or cowed, they expect a show and some sort of result for their efforts, and are disappointed when the old man ignores them. It is important to understand that the driving question is not whether the old man's wings are real, but if they signify a spiritual or theological purpose. Their expectation of entertainment instead of enlightenment is simply their reaction to that question.
The reactions of the crowds in this story seem to conform to Postmodernist ideas. The crowds are at first fascinated with the man and turn him into sort of a sideshow, but are quickly distracted by the spider woman, because they find her more fascinating and Marquez explains that "no one would ever doubt the truth of her horror." The Angel is then forgotten, because the people of the town, acting as one body, move on to another sensation and quickly forget the first. According to Postmodern thought, this reaction should be expected, because this theory claims that nothing will last the test of time, even the impression made by a so-called-miraculous being.