the idea that conspiracy theories are spurious is a result of mentally ill people irrationally latching onto them and far predates cointelpro. that said, it is trivially true that the world is run by conspiracies -- conspiracy is simply a label for private agreement for coordinated action, which carries negative emotional valence as a result of that association.
The idea that "conspiracy theory"===false comes right out of COINTELPRO. You know, the big secret (at the time) conspiracy to subvert domestic US movements. In fact, much of the 20th C was defined by secret conspiracies - the Bolshevik revolution, the rise of the Nazis, every post-colonial coup, etc. Project Echelon was well understood in the 80s. What is the USS Jimmy Carter even for?