Steve Lopez got it right. It's all about the Vatican letting those nuns know who's in charge — and it's not Jesus.
I was a member of the Immaculate Heart Community of Los Angeles in the 1960s during the Vatican Council's call for renewal of religious life. We studied the documents and voted on the direction the community should go. All the while, Cardinal James Francis McIntyre, L.A.'s archbishop at the time, used every power he had to crush the community's efforts.
Ultimately the cardinal won out and the nuns decided to step out from under the restrictions of canonical status and become a lay community. As such they have continued their work in education, social justice and spiritual leadership. They have become pioneers in an experiment in community, opening membership to men and women, married or single, who share the mission of Christ-conscious justice and equality for all.