How can a movie get this many elements wrong?

Diane Keaton overacts to a painful degree (we've seen her talent in other movies, so we know she is much more capable than this). The writers think that the "comedy" element of "romantic comedy" can be accomplished with silly sight gags like cakes falling on people's heads.

The overall plot has one seriously crippling flaw -- Mandy Moore's character two-times men to a level in which she's getting engaged to one and considering moving in with another! The viewer is expected to overlook her major indiscretions because she's cute and gets bossed around by her family. The writers would like to have us treat it as if she was going on a few too many dinner dates, not seriously manipulating the lives of two men.

I went with a female friend to see Because I Said So in the theaters because I figured I could handle a slightly silly romantic comedy, and I was willing to overlook minor flaws to get a few good laughs. I had to look long and hard to find redeeming qualities to the movie. Actors Gabriel Macht (as Moore's lovable, guitar-playing, easy-going romantic boyfriend) and Stephen Collins (as the father of Macht's character and a foil to Keaton's maternal role) are both outstanding. The other actors have rotten comedic timing or a forceful method that makes the viewer cringe instead of laugh. You will laugh at a few sight gags (a balloon stuck to the back of Moore's dress, anyone?), and Keaton's wardrobe is a stunning marriage of retro and modern stylings, but there is little else to hold this film together.