"While the continuity-of-teaching argument might have contributed significantly to [Pope Paul VI's] thinking [on reaffirming the Church's birth control prohibitions during Vatican II], it is also true that over the centuries the Church changed other long-standing teachings like those about slavery, usury, the earth's relationship to the sun, the use of the vernacular during Mass, and the theory that unbaptized babies went to limbo rather than heaven if they died. What seems to have differentiated the birth control debate from other changes in doctrine wrought by Vatican II were the accompanying implications for power relationships within the Church. What was different about birth control?
Had Pope Paul VI lifted the ban on artificial birth control, there also would have been an imperfect decentralization of power within the institutional Church. Once sex was disconnected from procreation, individual Catholics and individual priests would have to be trusted to work separately and together to evaluate the spiritual soundness of the sex lives of Catholics. Power and authority regarding sexual matters necessarily would become democratized with influence and wisdom moving up from the laity as well as downward from the hierarchy," - Mary Gail Frawley-O'Dea, Perversion of Power: Sexual Abuse In The Catholic Church.