There are plenty of old men who talk about that stuff too. Even WWII generation had a conspiracy theory about FDR conspiracy to let Japan bomb Pearl Harbor. There was even one about a second shooter in the Lincoln assassination. During Vietnam, there were plenty of conspiracy theories too. Some psychologists say fake conspiracy theorists stem from the natural instinct to identity patterns that allow people to predict danger. What was an important survival skill is now a comfort to those who can't handle the complexity of today's life.
I also don't think MarWan had a chance. He doesn't understand today's technology, which indicates to me that his education wasn't very good. Imagine growing up with a poor education and surrounded by the kind of myths he tells here to explain his reasoning. Some people believe every word of the Bible or Quran is meant to be followed literally. Not too different than the run of the mill conspiracy theory.
But, yeah, the speed at which conspiracy theories propagate these days is faster than the speed of light. It was just hours after 10/1 disaster when the myth of a Las Vegas second shooter showed up.