Revealing the truth all at once would traumatize many people, many of whom would experience psychotic breaks - this is true.
But it is also true that the consciousness of humanity is prevented from evolving by the denial of the recognition of its own shadow.
As in the microcosm, so in the macro.
The individual is best served by understanding what has happened to him, and the the reality of malevolence in the world.
Humanity is prevented from evolving so long as we are prevented from seeing the truth about ourselves - not only in terms of select evil actors, but in terms of our own willingness to ignore the signs that were always there, to allow the malignancy to spread to the point that the light of innocence was almost finally extinguished.
Humanity deserves the opportunity to go to the next level.
Unfortunately, this cannot happen without confronting its own shadow.
Q, you have a unique opportunity to catalyze a rough metamorphosis. Unique because it can be done in the spirit of freeing humanity, rather than enslaving. Unique because it is a careful and benevolent revealing, and not one of malice and sadism, as was almost our fate.
The psychological science of overcoming trauma and becoming well rounded and emotionally mature is clear on this.
Give humans the chance to move to the next stage.
The alternative is a perpetuation of arrested development, nothing deeply learned, and the inevitable recurrence of the same pathology in another cycle, in a time when all our wary anons and operatives are long since dead and forgotten.