Knocked-Up sucked. It sucked because the basic suspension of disbelief conceit (which we need to keep the whole system from collapsing!) was ignored by a director who would have us belief that a loutish, feckless, slovenly loser would be able to sleep with (I don’t care how drunk she was) a gorgeous, bright, kind-hearted, successful woman and then, after behaving abominably for months, win her heart.
Okay, I haven’t seen the movie yet. But I’m going to go out on a limb and guess that there’s only one word in that suspension-of-disbelief litany of adjectives that actually matters, and the word is "gorgeous." Take that word out, and my guess is the disbelief would suspend itself. You’ve never met a woman who was actively attracted by the prospect of re-making her guy? I mean, my wife is still trying to get me to stop eating with my feet. Yet, having examined my eating habits up close when we were dating, she consented to marry me anyway.
And it’s pretty obvious why you need the gal to be gorgeous: so guys come and see the movie. Otherwise this is a pure female fantasy: girl gets in trouble with the really wrong guy, but she’s got the chops to straighten him out and make an honorable man of him. And the guys stay away and the movie tanks. I mean, what’s the guy’s reward for becoming a minimally decent human being? A lifetime with Lili Taylor? She’s going to motivate the red-blooded couch potatoes of America to put on a clean shirt?
We’re animals, Jason. Animals.