Not many, only people who genuinely want to see the truth. And it takes integrity to admit if you are wrong which I did, so I don't have to live with contradictions in my head anymore.
It takes courage too. Going against deeply held beliefs is not easy. We often have a part of our identity tied up into that belief system. I understand where you are coming from. ...I had the same "talk" with myself a couple years ago about my political outlook which was derived in large part to my upbringing. Like you I didnt suddenly jump into the other camp but stepped back and question the entire system.
I didn't went from deeply held beliefs to something else. I already knew this, I just tried to rationalize and lump together 2 contradictory things. I should have been critical and selective about certain items. Perhaps that is the propaganda, to try to put something evil in the good basket to mask itself.
It's also a psychological barrier in some way. People feel they have a vested interest in being right and in a social context not losing face.