I don't think the article is even fact based to assume youtube has created a conspiracy theory boom. I remember the dial-up age and people typically knew some corner on the web for reading conspiracy theories to get some laughs. When 9/11 happened there were those conspiracy documentaries and this was before youtube was what it is today. My guess if a boom is being created. The reason is from people being crafter at getting people absorbed in the conspiracy theories. Maybe the health & happiness of society has decreased and where people are now easily absorbed into conspiracy theories. Misery is a beast that pulls people into time sink holes to escape reality.