The reason for this change was the ultimate nature of the Guanyin. It is a kind soul that never turns a person in need away. There were stories of miraculous things happening when the common people called on Guanyin. People usually see women as kindly and merciful. So it would only make sense to people to have a feminine form to look up to. It gave the people a sense of calmness. Another reason for this change is that many women believed in Guanyin and look to her for strength in times of injustice. It would only be logical for Guanyin to be a woman.
Guanyin (or Avalokiteshvara) is a saintly Buddhist figure of Indian origin. Known in the West as the "Goddess of Mercy" (circa 706 A.D.). Guanyin, an all-powerful enlightened being. Bodhisattvas are those beings who have progressed spiritually to the point of enlightenment, yet choose to remain on earth to help others reach similar spiritual heights ("he who hears the cries of the world" or kuan " looks on", Shih "the region of sufferers" Yin "whose voices ask salvation from misery"). Chinese people were not able to fully understand and welcome the concept of enlightenment, which was established originally from India, because it did not have much appeal to them. Enlightenment required an individual to detach himself from family relations and all material things. This seemed a little far-fetched for the Chinese because family has always been an important part of a person's life. Therefore, Guanyin was perceived as a gracious bodhisattva who they could look up and relate to. To pay reverence to Guanyin there need not be a detachment to family. The Chinese people has selectively admired a deity that best suites them. Unlike the Buddha, the bodhisattvas are decorated with jewelry to indicate their ties to this world. Buddha, a creature that has reached ultimate enlightenment, meaning that it has moved from the living world to a world of utopia without the need of personal possessions.