So Insight calls them fools because willingly surrendering like this allows a mind mage to more easily access and change core aspects of their minds. Greater subtlety and more drastic changes are possible. Conversely putting up too much of a resistance can break a person's mind. But this would be like pitting two walnuts against each other to see which one breaks first. Giving up like this is like throwing yourself upon their mercy. The Prisoner is using intimidation and sexual attraction and showing that he keeps his promises as a way to gain the easy surrender. 'Obedience will be rewarded.'