Because rituals involve material objects and because there is a system as well as a defined goal, a person's expectations grow and become vivid. When someone performs a ritual and the expected results don't occur, as is usually the case, that person becomes disappointed.
In order to cope with the disappointment, the person tries to discover the mistake in the ritual. Then the interpreter, who is usually the priest, takes advantage of the subtle tendencies of the mind of the person performing the ritual and puts the entire blame on the performer:
"You didn't do it with the right attitude of mind; you did not follow the exhortations correctly; you did not give the appropriate love offering to the officiating priests"; and so on.
Such explanations create and perpetuate guilt.
As the ancient portions of the revealed scriptures state, the original rituals were a simple means of channeling one's devotion toward the divine. They did not require help from priests and clergy.
However due to ignorance, laziness, or the tendency to lean on others, aspirants want their rituals to be done by someone else, namely a priest.
In order to display their expertise and impress their clients, priests elaborate the rituals, causing them to become riddled by dogma and superstition.
Source: The Tradition of the Himalayan Masters by Pandit Rajmani, Ph.D. Tigunait