Many people are presented with 2 alternatives: Alternative A) You are an ordinary person with an ordinary job and ordinary pasttimes. You fulfill your role in society like everyone else. Alternative B) You have an important mission that will change the course of history, to spread the influence of . If you are bored, tired of living a repetitive life and have no purpose in life, Alternative B) sounds fantastic. Now y…
Actually, I'd disagree. If you dig in to a lot of these theories, there is a kernel of rationality behind them. Many adherents can actually rebut arguments with evidence that makes a surprising amount of sense: there are usually multiple possible explanations for individual phenomena, and if you look at them in isolation, it can be very hard to conclusively demonstrate that the "scientific" answer is actually the best possible explanation. This to me explains why even intellectuals can fall prey to these theories: if you already have a nonconformist streak, the alternative explanations can be interesting to dig into.
Where they fall flat is in overall coherence; these theories often end up with massive gaping seams if you try to expand them from explaining one phenomena. And these seams are so obvious, and yet adherents have no coherent explanation for these seams, that it overshadows whatever kernel of rationality the theory originally had.