re the 'intelligence/education' remarks - I don't necessarily think it is a lack of education or intelligence (although there are some where it applies!), but the fact that even those who are intelligent and educated have been told for so many years to switch off their natural curiosity and questioning ability and just accept, obey, nod in agreement etc. - it's like you're in a fog and you can't see clearly. That and the high demands on your time and energy and pressure to conform means that it's hard to come up for air...
I heard about a social experiment 'the smoke filled room' where they had a group training session taking place, one person thought he was really there for training and the rest were actors...during the session, smoke started coming into the room from the ventilation shafts, none of the actors responded they all just carried on in the group activity as if nothing was wrong - so the genuine guy didn't do anything either, he just went along with the crowd.
When we are surrounded by people nodding in agreement, accepting and not questioning, oh and we're exhausted - it is very hard to sit up and say, hang on a minute, this is a load of ****!!