Very eloquently written. I like the way you think - followed.
I think that confirmation bias has a role to play in many pseudo-scientific claims as well. Individuals look for evidence that confirms their theories and they conveniently ignore the cases that go against them. Ideas that are confirmed, become ingrained within us.
I think that ego (as in the "self" or identity) also plays a role. Ideas become a part of who a person is and the individual becomes attached to them. This is why people often get defensive when we question their ideas. They aren't just defending their idea, they are defending themselves.
@xmachina is your name derived from the movie Ex Machina? That was one of my favorites.
RE: The Power of an Open Mind