This sort of question is the type that can strain the
allegory of a story into breaking. A series like
Star Trek cannot be taken too literally (the need for "in universe" explanations for
everything by some fans).
Without becoming too specific and risk being "too political" for the forum, we've seen many psy-ops in history that require little more than a "hollow tube" to enthrall the susceptible with some
controlling idea. (Here is one place where we must take Spock's statement about "hollow tube" literally—no in-universe cop-outs that maybe the material of the tube contained technology too esoteric for Spock to understand. It was, as he said, a hollow tube. Just that. A symbol with no technology behind it.)
There is a demonstrated "herd effect" for people to go along with others, even when they can see that the herd is "wrong" about something:
Sometimes all it takes is one little boy to point out that the Emperor is naked to break the spell. And there are other documented cases where the "brainwashed" will continue to believe the propaganda, no matter what evidence is provided. Or as Mark Twain put it, “It's easier to fool people than to convince them that they have been fooled.”