There’s a popular notion among New Age circles that we create our truths, and the world conforms to our beliefs. A somewhat weaker notion of this is that the Truth is so subjective, it’s essentially just something we pick, and the rest is interpretation. No one having a monopoly on Truth could be seen as supportive of this idea.
I’d argue for a simpler interpretation. We are limited in our capabilities to gather data, and to come to correct conclusions. We need to to that in a community. We also have different values. Those too matter in terms of our relations with one another. The anti-monopoly stance is the recognition of the differences in the community, and what that means. And you can stand in complete defiance of the community; but there is always what Sartre described as the Look or the Gaze, where there is still the sense of other people trying to define us.
