Similar to ideas about the Bible, where it all must be true, because if some of it isn't true, the whole belief system could fall apart.
This way of thinking shows itself in attacks on evolution, where the creationists try to find a flaw, any flaw in current evolutionary theory, somehow believing that if they find a mistake, any mistake, the whole thing will fall apart.
So we must believe that Rush, etc, are infallible, because if they're ever wrong, how can we ever have faith in them again?
Just my guess. Of course I think someone who refuses to admit any mistake is a bit crazy... but I'm an atheist. Until proven wrong.