Why did Islam legislate marriage to more than one wife?

God Almighty legislated polygyny for apparent wisdoms and benefits, among them that the number of women is greater than men. If a man were to be restricted to one wife, many women would be deprived of marriage and the fulfillment of their natural urges, which could lead them to commit illicit acts. Another benefit is the increase of the human race, which is unified in worshipping God. Another is solving the problem of a wife's infertility without divorcing her. God permitted this with regulations that ensure everyone's rights. One might ask: Which is more oppressive to women—God's legislation, which contains justice and protection, or the callers to immorality who prevent her from marrying a polygynous man yet permit her to commit adultery, thereby depriving her of marital life and pushing her towards immorality and raising illegitimate children?