It's the same reason predators have been flocking to adopt these identities. You create a sacred caste that you're not allowed to question and unscrupulous people are going to become a member of that caste. These people are happy to go through years of training as priests or teachers or years of ingratiating themselves in the community as scout leaders. "I am what I say I am" is a golden opportunity for people like this, since they don't even have to put in any effort beyond a simple statement of faith