The film see Kidman, as stuck up New York writer type go back to the family home (which Leigh now owns) for her sister's second go through at marriage (this time to Jack Black).
As the film progresses, we see how dysfunctional families can be as they relate to each other. This made me think 'Well, no-poop Sherlock.' The fact is no family is perfect. We all have our quirks. This family has more quirks than most (and Kidman is one of the most unpleasant people I've ever seen portrayed on screen), but did I have to sit through 2hrs of film to learn that?