While I'm reviewing one particular movie adaptation my comments probably apply to other adaptations, and to the book, as well. Universal happiness keeps the wheels of society steadily turning. As a final means of control, the citizens of the brave new world are also addicted to an intoxicating drug, Soma, which keeps them in a constant state of happiness.
Unorthodoxy threatens society.
In this Utopia, there also exists a Savage Reservation where people who've chosen to not live this lifestyle exist. Even though it's obvious they're brought in as novelties to be gawked at, Cooper enters the brave new world with hope and excitement. He is soon disillusioned by the superficial lifestyles and the lack of passion, and starts encouraging disobedience and violation of the Utopian rules. Promiscuity is a citizen's duty. Everyone belongs to everyone else.