It might disrupt their beliefs that they have held dear their whole lives. I use to know a guy, about my age, that believed, without fail, everything his daddy ever told him in life.And you could not change his mind even if you showed him written proof. For example, his daddy had told him you have to be a lawyer to be a politician. He would argue the fact that “My daddy said....” and refused to believe that maybe his daddy was wrong here or there. He was a spoiled only child growing up and even as an adult, depended on what his daddy said or thought to get him through life.
“believed, without fail, everything his daddy ever told him in life.”
And I was the exact opposite when it came to believing my father.