One proposal is that religion is the cargo cult built around the fossil of a once-living system that worked or was relevant for a particular time, place, and group of people.

So in the case of Scientology, perhaps there was a set of techniques that worked for one reason or another, and people still swarm around the dead husk - the empty rituals. The why is obvious; control and greed. Two things that are almost guaranteed to kill something delicate and living.