To add to OP's points, most people aren't self aware. In the 1930s it was perfectly acceptable to be racist and few people questioned this. Likewise, few people today are willing to bring their own beliefs under scrutiny... at least until someone in a position of authority tells them to do so. People walk around so sure they are right about everything, that incels are evil and women can do no wrong, but at any moment everything they believe could be proven to be false. Yet when the paradigm shifts, everyone will be walking around just as confidently believing in whatever the new truth is thought to be. Like you said OP, most people are basically incapable of independent thought, which is why we have the NPC meme in the first place.
