The Emperor has no Clothes

The origin of this phrase comes from a Hans Christian Anderson's fable The Emperor’s New Clothes. A vain emperor spends a vast amount of money on clothes. One day a couple of con men pay him a visit and offered to make him the most expensive clothes ever which would have a magical property of being invisible to those unfit for office or who are simply stupid. So the emperor ordered that they be made. Of course the con men made nothing at all but pretended they did. Since no one wanted to appear to be incompetent and stupid, everyone, including the emperor, pretended they could see the clothes. But one day a small child piped up that the emperor has nothing on. The bubble of pretence burst and everyone then admitted they could see no clothes either. 

We pay lip service to certain ideas because everyone else seems to subscribe to them and we don't want to appear to be idiotic, or even a loon. But then certain ideas are perpetuated, not because of their intrinsic merit, but because no one dares say anything.