The examples I gave were just that: examples. I can see how it was a power driven thing, but the idea behind them were widely accepted. To use the same issue I used in the post, even women used to consider themselves inferior and incapable to have a job or own property, because that was the general belief.
Even the unimportant things are changed through minority influence. Think fashion or styles. New ones come up when a few people decide to be different, to wear weird clothes or do their hair in a special way. Then more and more people join in until it becomes a trend.

Thank you so much for your comment! :)