This also applies to certain "conspiracies."
In both cases, it's their God of the Gaps.
(Not to be confused with the Boss of the Ross. Or Hermes. Or Nike.)
Conspiracies are wonderfully self-reinforcing: anything that doesn’t support the conspiracy is clearly the work of the conspirators hiding their existence.
One of the problems is we do have massive gaps. Mainly because we have no written records from the Stone Age, and barely anything from certain other cultures. Von Däniken exploits that.