Humanity has many systems of tricking people to do various things harming their own self interest, but saying what people believe has any inherent value is a huge mistake. Trump getting elected is going to kill many (though hopefully a small percentage) of his supporters, but many of them don't see a problem with this.

Trying to be a hero running into a hail of bullets it stupid. But, hundreds of millions of young men have repeatedly done so. Watching a war movie most people cheer such stupidity on as a good thing continuing this cycle.

PS: Many people hate this but even a single counter example absolutely disproves what you say. Yet, convicting people to believe lies has long had value to a great many people, so pointing this out is generally a waste of time. People even react negatively to the truth note all the down votes for polite on topic responses.