I feel the author badly misses the point here. It's not that a person in difficult conditions will necessarily suffer horribly from knowing bad things; they might give up in despair, or they might rise to the occasion and do something startling with the limited options that are available to them.
What's really being protected here are the feelings of the more knowledgeable people; preserving an illusion for the vulnerable serves as a reservoir of hope for those already in despair. This is the 'noble lie' of Plato's Republic (sometimes referred to as a 'pious fiction' in religious terms; likewise the field of law is awash with 'legal fictions' that everyone knows are fictional but which are easier to maintain than addressing the underlying problem). The false picture of a reliable teleology serves to soothe the anxiety that would arise if it was widely appreciated that the people in charge don't know what they're doing a lot of the time and are just making slightly better informed guesses.
While individuals, tribes, and small societies can overcome that anxiety, accept uncertainty and persevere or even thrive, the larger a society becomes the more difficult it is to promulgate ideas and actions within it, and (perhaps more importantly) the greater the incentives for those who benefit most from the fiction to uphold or elaborate it at the expense of others.
Of course, most of us are wired to be protective of children and minimize unnecessary anxiety in favor of harmony. It can be both a kindness and good strategy to shield the vulnerable in hopes that they'll make it through bad times relatively unscathed. But taken to excess, it robs individuals of their agency for the sake of a comforting sentiment, imprisoning them in a gilded cage for the nostalgic pleasure of their jailers who are mourning their own loss of innocence. Should the cage be breached, the unwary inhabitant may fall from a cradle into a horror for which they are utterly unprepared, a far crueler fate than the most pessimistic decline.
What's really being protected here are the feelings of the more knowledgeable people; preserving an illusion for the vulnerable serves as a reservoir of hope for those already in despair. This is the 'noble lie' of Plato's Republic (sometimes referred to as a 'pious fiction' in religious terms; likewise the field of law is awash with 'legal fictions' that everyone knows are fictional but which are easier to maintain than addressing the underlying problem). The false picture of a reliable teleology serves to soothe the anxiety that would arise if it was widely appreciated that the people in charge don't know what they're doing a lot of the time and are just making slightly better informed guesses.
While individuals, tribes, and small societies can overcome that anxiety, accept uncertainty and persevere or even thrive, the larger a society becomes the more difficult it is to promulgate ideas and actions within it, and (perhaps more importantly) the greater the incentives for those who benefit most from the fiction to uphold or elaborate it at the expense of others.
Of course, most of us are wired to be protective of children and minimize unnecessary anxiety in favor of harmony. It can be both a kindness and good strategy to shield the vulnerable in hopes that they'll make it through bad times relatively unscathed. But taken to excess, it robs individuals of their agency for the sake of a comforting sentiment, imprisoning them in a gilded cage for the nostalgic pleasure of their jailers who are mourning their own loss of innocence. Should the cage be breached, the unwary inhabitant may fall from a cradle into a horror for which they are utterly unprepared, a far crueler fate than the most pessimistic decline.