Serious question.

Why cling to a widely discredited conspiracy theory? The discrediting sources are usually held to be more or less trustworthy at other times. For example, most important news from CNN, Fox, the BBC, etc., is more or less true; the engineers who insist that no inside job was needed to bring down WTC are real engineers; and the New York, Washington, and Federal law enforcement agencies do a pretty good job of investigating crimes. It would be pretty spectacular for them all to be either in cahoots or else unbelievably gullible, wouldn't it?

If the sources are right, the conspiracists are deluding themselves and wasting their time. If the sources are wrong and/or lying, how does that affect the conspiracists' daily lives? Or does it?