Biff's view of his father after Willy's death has to be seen as a frail attempt to justify Biff's own inability to accept and deal with his father. Biff spent much of his life doing exactly what he was accused of by Willy: acting spitefully. Willy's dreams were actually quite simple and at the same time universal. He wanted a better life for himself and his family. He wanted his children to be successful. He wanted to fulfill his American dream of success. Willy was wrong in believing that the secret to success is in being well liked, but it was his understanding of the world of business that was at fault, not his dreams. When Willy was unable to achieve his dream, he tried to pass it along to Biff; however, when Biff discovers his father has human frailties, the son turns on the father, spurning any chance to be successful in his own life and then blaming all of his failure on Willy. Willy is flawed, not only because of his extramarital affair, but because he built a life made of lies. In spite of this, Willy's dreams are valid. He certainly cannot be accused of not trying to succeed. Imagine how painful it must have been to him to travel so far and earn so little for his efforts. In the end Willy sacrifices his own life for Biff. Is this the dream to which Biff was referring, the dream that his son would enjoy success in life? It is not the dream that is wrong, it is the son who is unable to live up to the dream. At every turn, Biff fails his father, and the great tragedy is that even in the end he cannot relent. He must blame Willy and trash Willy's dreams, and be extension, Willy's life or he must take ownership and responsibility. We never see Biff live up to the love his father felt for him. The flaw was not in Willy's dreams but in his son's inability to forgiveanyone, himself included.