Project Monitoring -Why is it necessary?

Assuming the members of a Project are all responsible and knowledgeable people, why do you think Project Monitoring is necessary? I have a fundamental priciple as the raison d' etre for a need for project monitoring. It lies in the Second Law of Thermodynamics whose statement in one way is "All systems left to themselves will move towards entropy(Disorder)". Now take PM as a requirement that suggests itself because of this principle embedded in Nature. You leave a Project unmonitored, it will move towards chaos at worst. Silp out of hand at best. So, Project Monitoring is a necessary Evil?