I think it has to do with self-reflection and introspection. I don't think the average person is capable of it to a large enough extent that it allows them to actually internalize and think about their beliefs. They simply hold those beliefs because their in-group does and being a part of that in-group feeds them. They hold feelings and not examined thought. Legitimately, I think this all comes down to the average person isn't able to mentally function at a high enough level to parse out all the info they now receive, weigh that info against all the other they see, and then actually think about the implications to their personal values, morales, and life. I think most of them accept the list of right and wrong given to them by others.
I think the average American has too low of EQ and IQ to live in the internet age.
