Indian psychoanalyst Sudhir Kakar writes:
I have mentioned above the dangers of the guru role lie in the disciples' massive parental projections which the guru must process internally. Although the guru shares this danger with the analyst, or more generally, with any healer, the intensity of these projections, their duration, and the sheer number of devotees involved are vastly greater than in the case of his secular counterparts. These idealizing projections are subversive of the guru's self-representation, constitute an insiduous assault which a few gurus---again like some therapists---are not able to successfully resist. A regression to an omnipotent grandiosity is one consequence, while in the sexual sphere a retreat into sexual perversion has been reported often enough to constitute a specific danger of the guru role. (The Analyst and the Mystic, 53-54)
So it's a general mechanism that the gurus themselves fall victims to their own power of initial attraction.