In response to Fethi Benslama's questions about what happened to impede gender parity in Islam, here is an excerpt from Leila Ahmed's book "Women and Gender in Islam:
"'Umar's reign (634-44) is regarded as the period in which many of the major institutions of Islam originated, for 'Umar promulgated a series of religious, civil and penal ordinances, including stoning as punishment for adultery. He was harsh toward women in both private and public life: he was ill-tempered with his wives and physically assaulted them, and he sought to confine women to their homes and to prevent their attending prayers at the mosques. Unsuccessful in this last attempt, he instituted segregated prayers, appointing a separate Imam for each sex. He chose a male imam for the women, another departure from precedent, for it is known that Muhammad appointed a woman, Umm Waraka, to act as imam for her entire household, which included, so far as can be ascertained, men as well as women (Ibn Sa'd, 8:335). Moreover, after Muhammad's death 'Aisha and Umm Salama acted as imams for other women (Ibn Sa'd, 8:335-56). Contrary to Muhammad's practice, 'Umar also prohibited Muhammad's wives from going on pilgrimage ( a restriction lifted in the last year of his reign). This prohibition must have provoked the discontent of the Mothers of the Believers, although "history" has not recorded any opposition on the part of Muhammad's widows to 'Umar's attempt to prevent women from attending prayers at the mosques (Ibn Sa'd, 8:150). The consistent silence on such issues now speaks eloquently." (1992, pp. 60-61).
~Excerpted from "Women and Gender in Islam" by Leila Ahmed, PhD. She was professor of women's studies and Near Eastern studies at the U of Massachusetts, Amherst and is currently on the faculty at the Harvard Divinity School.