Barbara Ehrenreich's book Bright-Sided: How the Relentless Promotion of Positive Thinking has Undermined America, and she supports her thesis very well.
She's not saying that positive thinking is bad in itself. She's a remarkably cheerful person here, despite having had to suffer through the pink optimism associated with breast cancer, as well as the disease. What she objects to is the substitution of superstition and optimism for real information and real action in the real world, a world that remains complex despite so many people's effort to oversimplify it.
And if you are constantly told that you won't be cured unless you are blindly optimistic, that's a bitter pink pill to take. It's not that positive thinking might not indeed help the healing process! It's that if you are not cured, you would be blamed for that. Meanwhile, carcinogens still go into the environment, thanks to big business practices. Meanwhile, mainstream state-of-the-art treatments for cancer continue to pour toxins into the body, etc.
Yes Man, to see motivational speaker Terrence, played by the charismatic Terence Stamp, and Baby Mama, to see business guru Barry, played with giggle-producing calm intensity by Steve Martin, in action as the kind of money-making manipulators who benefit from blindsiding those around them with the need to be positive. I love how both films gently mock the gurus while demonstrating their undeniable success.
One of the book's sentences that sticks in my mind as "Most of the money is made at the back of the room" (at motivational speaker events) is evidenced in the scene from Yes Man, where, even before Jim Carrey hears the great "Yes!" speaker, he's there buying books and DVDs in a labelled plastic shopping bag that continues the relentless promotion of positive thinking.
Comedy is such a great way to criticize society. The viewer gets to laugh and make her own choices.