Cracks began to appear in the cover-up early on, but were mended by intimidation. This took the form not only of threats and beratement, but physical harm, to person and property, and even death. The rationale was that so much more injury and devastation would occur, were the populace to panic, that this was justified. For decades this was the rule, with active disinformation to smooth the edges. Over time, the amount of disinformation increased, until the whole situation became awkward and, quite frankly, untenable.
Disinformation is a tool designed to deal with short term or delimited affairs.
With the alien presence, which has been dragging on and most certainly will not go away, the disinformation spread about began to be more of a problem than the rumors of the alien presence. Trust went out the window, and the public has become too cynical to believe anything that comes from government spokespersons. Added to that is the dilemma that the cover-up crowd is increasingly facing, that being that their stories are beginning to meet each other, and clashing. The cover-up is dropping not only because it is difficult to maintain, however. Those in the government in charge of handling the alien presence, who are generally known as MJ12, desire the public to become aware.