This is a great question. The Joy Luck Club is a great book and there are many points of view. In fact, there are no less than sixteen stories interwoven among mothers and daughters of Chinese descent, as they reflect on their lives. In light of this, let me make some comments.
First, because there are so many perspectives, the reader gets a real sense that the novel moves quickly. There is not one consistent voice, but many voices. The reader likes some of these voices and perspectives and does not like others. There is a natural comparison that takes place. Also the authors captures the reader through so many voices.
Second, with all of these perspectives, the reader is forced to ask from whose perspective the stories are being told. Is it the author's voice? Is it the narrator's voice? Moreover, as these perspectives valid? In literary circles, this is called focalization.
Finally, these many perspectives make the novel complex. It becomes truer to life. In the end, the reader is able to relate to some of these voices.
Author Amy Tan wrote this semi-autobiographical novel in the voice of eight different women. Though it has sometimes been criticized for being confusing and hard to follow because of the various points of view utilized in character, place or time, the differing points of view are what draw the reader into the worlds of the characters, making their stories that much more interesting.
As the reader reads along, experiencing each character's story in different times and places, he is taken along for a ride through each time and space. Sometimes this feels disjointed for a reader and causes confusion if too much thought is put into figuring out the storyline rather than reading and waiting for it to unfold. These feelings that the reader experiences mirror the way that the daughters and mothers felt throughout life as they tried to understand each other's cultural point of view.
By employing this shift in character and point of view throughout the book, Tan not only makes each scene and subplot that much more realistic but she also creates a body of work that reflects the reality of being these mothers and daughters with such great cultural differences. Thanks to Tan's masterful writing in differing points of view, the reader experiences some of the same feelings the daughters and mothers did as they tried to understand each other's point of view. Writing in differing points of view is a stylistic choice that Tan uses that actually matches one theme of the book, understanding others' points of view.