It's probably for the best that most of us wouldn't know each other from.......................... if we passed in the street so I fail to see how it becomes possible to make claims about people having vendettas.
IMO, it's no easy thing to find one's mind changing. It flies in the face of belief systems which have been held close and the ground on which one has been standing no longer feels quite as firm. It's probably much more comfortable to admit than to go on denying. I could give numerous reasons for doing this but the ultimate responsibility for it is my own. I can't lay the blame for it at others' feet. What starts with tiny, niggling doubts expands to the point where one's reasons for hanging onto the old belief are no more than futile excuses. Caroline and Susan should be commended for having the courage to talk about it.