There are obviously a lot of conspiracies that really do go on, usually engendered by the wealthy and powerful so as to become even more wealthy and powerful. But the fashionable conspiracy theories are generally so astoundingly stupid that only really damaged people find them attractive. The degree to which some of the most moronic ideas (they are definitely not "theories" in the real sense of the word) have become popular speaks volumes about the lack of general education in the population at large, and the lack of even the most rudimentary capacity to perform deductive reasoning. Conspiracy theories are the mental equivalent of junk food: something only low-status low-IQ individuals find satisfying.