Many schools of thought, both practical and metaphysical, mix factual information with superstition. This creates confusion in the student who earnestly attempts to unravel fact from fiction and those ideas which are useful from those which are not.
Some people swallow all the teachings of a given school in one gulp, thinking, illogically, that if part of a teaching is true, then all of it must be true. Such unquestioning obedience to authority and dogma creates a situation where outsiders tend to view believers as deluded and the whole school of thought as invalid, due to their perceived blind adherence to superstitious thought.
This is a shame because many useful facts and ideas are contained within many of these schools of thought, if only they can be sifted through and found. But for this to occur we must have an open, inquiring mind, and not be subject to slavish adherence to tradition and the edicts of authority figures.