CIA document 1035-960
Countering Criticism of the Warren Report
so , yes, it is a derogatory term created by the central intelligence agency to delegitimize Americans who asked too many questions about President Kennedy's death. It has spread to any subject since then.
Whenever you hear someone dismiss cold hard facts with this you know, unfortunately, they are a brainwashed to react this way in order to maintain control over their own minds & those that they have influence over. Be it business, personal or political.
After all, if the truth and the depth of corruption were truly known. There would be a riot in hours.