Apart from the other points, I feel that this would have the opposite of the intended effect. The existence of morality police would compromise other motivation

Apart from the other points, I feel that this would have the opposite of the intended effect. The existence of morality police would compromise other motivations to be moral, in the same way that offering small amounts of money for blood donations causes donations to decrease (because the social kudos from doing it for free is a larger reward than the money).