Why do men and women not get to choose who they marry?

Relationships are forbidden, there is no marriage. Families do not exist, babies are a result of eugenic mating, which is decided upon by the Council of Eugenics, who partner the men and women. Love, loyalty, and connection are considered dangerous, everyone must remain a part of the whole and follow the directions they are given without question.

For men are forbidden to take notice of women, and women are forbidden to take notice of men.

And we take no heed of the law which says that men may not think of women, save at the Time of Mating. This is the time each spring when all the men older than twenty and all the women older than eighteen are sent for one night to the City Palace of Mating. And each of the men have one of the women assigned to them by the Council of Eugenics. Children are born each winter, but women never see their children and children never know their parents. Twice have we been sent to the Palace of Mating, but it is an ugly and shameful matter, of which we do not like to think.