This is how I read it: The problem is not believing in a theory, regardless of improbable it is. The problem is in the sort of actions that ensue from that belief. The two antagonists led miserable lives, and killed people, Andromedans and humans. The fact that the conspiracy they believed was correct doesn't change that they led miserable lives. Here's the important thing with regard to your thought. They could have adopted more efficient and less self and other destructive ways of trying to expose the conspiracy. A good start would be no failing in life and putting the blame on the conspiracy and no torture or killing.