The child symbolizes unhappiness, negativety, and/or the bad. The child is a symbol for anyone's problems. As we go through life, in order to appreciate the good things that come out of it we must know what rock bottomis, to imagine or have experienced the bad. Without rain there can't be sunshine. There is no joy without grief. There is no success wihtout failure. The one's who walk away from Omelas portrays this sense of ying and yang. In life there must be a balance.