It was composed at a time when barbarians were about to conquer the city. On the night on which it was prayed, the barbarians mysteriously left and never came back. The Church has kept this prayer which God so profoundly honored. The common objection to read prayers are that they are not sincere. But this is not necessarily the case.
People read vows at a wedding or even memorize what they say.
In fact, human beings very carefully choose their words when they really have to mean them. Remember, this is how people act at special occasions before special people. Humans usually like to repeat what they love. Favorite, oft-recited portions of scripture such as Psalm 23, the Lord s Prayer, and the Beatitudes, all serve to illustrate this. These are repeated by the same people over and over.