The opening montage of Because I Said So sets up the movie’s touchy mother-daughter dynamic: Home videos from post-WWII suburbia show homemakers triumphantly surveying their domestic domain. As she approaches her 65th birthday, single and lonely Daphne Wilder (Diane Keaton) has trouble letting go of her sexually liberated daughter Milly (Mandy Moore). Daphne fusses over every detail of Milly’s life, from boyfriends to the placement of a flowerpot on the coffee table. Because, you know, it’s “hard” to love your children so much.

It’s a study in hate-love, except Diane Keaton is purely hate-able. Her obnoxious performance is an escalation of the actress’s Woody Allen-like neuroses, from her twitchy mannerisms to her falsely elegant sense of style. She is that crazy white lady in the big belts and bad bangs, the kind who gets laryngitis from crying too much and asks her daughter what an orgasm is like (No wonder she’s so wound-up — the woman has never masturbated!).

In certain fundamental ways, it’s impossible to separate Keaton from her character. Daphne’s gaudy wardrobe recalls the actress’s mannish garb: For both, style is an artificial form of self-empowerment. Keaton and Daphne both involve themselves in creative activities — photography books and baking, respectively — as a means to maintain their “independent” spirit. And both women fancy themselves shining examples of feminism, although the world is secretly tired of their self-absorbed whining, a real cultural death blow to wealthy white women, for whom Keaton has become some sort of perverse icon.

This isn’t flattering for Keaton, or the women who continue to patronize her movies. If the pleasantly goofy Annie Hall is any indication, neither Keaton nor her movies have aged very well. Now starring in lifeless romantic comedies that are trivial upon release, Keaton has gone from silly to stupid.

The moment of irrelevance came in Something’s Gotta Give, when Keaton’s character ignorantly panned all rap music as misogynistic. Her movies appeal to women too smart to stoop to such a judgmental view of the world, except they’re too wrapped up in romantic fantasies to engage with contemporary life. Even bad rap music — the misogynistic kind — deals with modern ideas. Keaton and her producers peddle rom-com fluff for bored baby-boomers.

In an ideal world, Because I Said So would be satire. Instead it struggles and fails to engenger the audience’s sympathy for Daphne’s, err, problems. At least Milly has her head screwed on right: At one point, she says about her mother, “I can’t even look at her right now.” A no-nonsense, natural beauty, Mandy Moore charmingly underplays her role. She is the antidote to Keaton’s antics. If only her strong-willed ethos was the emotional core of this film.

In a recent Slate article, Dana Stevens complained that Keaton no longer stars in good movies. Because I Said So is a miserable movie, but it’s not Keaton who’s dealt the bad hand. She’s part of a sinking ship. And if there’s any justice, Moore will be the one with the comeback.