Conspiracy theories are a political tool these days.
You can encourage a conspiracy theory to make the other side look like fools for believing them. You can use them to frighten your own side into remaining on the plantation.
Cass Sunstein wrote extensively on the use of conspiracy theories in politics. He's a progressive scumbag but he's smart enough to know that there is a sizable percentage of the American public that desperately wants to believe that they're privy to some great secret. Unfortunately being privy to the "great secret" tends to make people resistant to even the most obvious truths.
For instance, at TOS there were a lot of posts about "secret" military operations here in Michigan a couple years ago. I went and posted several news stories from weeks and months prior that alerted people that the military would be doing it. Those stories were ignored by virtually everyone because they had already decided that they were in on the great secret.
The Ancient Aliens guy has made a living by directing viewers away from obvious facts and suggesting fanciful explanations completely devoid of fact. Just because we don't know every detail of how the pyramids were built doesn't mean there is anything to suggest alien help. The fact is we do know a great deal about their stoneworking methods and how they got straight lines and alignments.
Someone once challenged me with the question, "Why can't we build pyramids today?" The fact is that pyramids are a common modern architectural design used wherever they're needed. They aren't built of stone as stand alone structures because that would be a waste of time, money, and material.
