That's what sports, movies, US weekly and reality tv is for.
But there are people who are interested in politics. And with subcultures like ours there are always going to be a few conspiracy theorists. They're usually crazy and wrong about 90% of what they post. But the other 10% might have some substance and the conspiracy theories discredit that 10%
The mere existence of conspiracy theories has the ability to silence legitimate criticism of government under the guise of the critic being considered a lunatic.
For an analogy, consider the birthers. A lot of birthers may have had legit criticisms of Obama but who is going to listen to a birther?