Sky,
I think, for me, it is because of the many experiences I've had with people who are rigid in their beliefs. I am employed with several people with whom there is no basis for any kind of interaction based upon their belief system, which is a fundamentalist Christianity in which they rule me out in even casual conversation. I have learned not to try to relate to them after years of interaction and trying to converse. I'm just flawed to them.
Also, in my long, unhappy marriage, my inlaws were the same. I spent much of that time trying to fit in with them, but they were so judgmental, I finally quit trying!
I am speaking the truth here about people with whom I have and am interacting daily.
I grew up totally immersed in the Protestant religion, and I still retain much of it in my unique belief system, but I would never reject people who have found a different way.
Patty