What was the impetus for restoring the consecration of virgins for women living in the world in the 20th Century?

The United States Association of Consecrated Virgins says the following about their sacramental: > The Consecration of a Virgin is one of the oldest sacramentals in the Church, and one of the fruits of Vatican II was the restoration of this profound blessing on virgins living in the world. The promulgation of this restored Rite for women living in the world was on 31 May 1970. What was the impetus for restoring the Consecration of a Virgin for women living in the world? As it says, this is an old practice, but seems to have fallen out of favor after a time, so I'm curious as to why it came back.