The value of religious education is highly dependent upon the teacher.
Just like any type of education you can obtain. The majority repeat what they were told and believe that to be truth (maybe b/c it's easier?) while a much smaller percentage of people question everything in order to gain a deeper understanding.

The latter usually make the best teachers and they exist, albeit in small quantities, in any religious institution. Unfortunately, many religious institutions will try to whip the "truth" into you via fear.