But at some point, once a group like that starts to grow, and its blood has trickled for enough time, it inevitably bleeds into haemorrhage, and at this point it becomes externally pervasive and internally overwhelming. The only distributed stupidity groups that can survive this are the ones where the emotional appeal of their indoctrination strategies are such that the members feel the emotional duress of leaving or questioning it, for fear of heretic-hunting.
A good rule of thumb with the majority of the members of these groups is, always assume blithe cowardice, weak-mindedness, lazy indifference or wilful individual ignorance before you assume a thought out collective philosophy, because they are a lot rarer than you think.