So many stupid things societies do are the result of an unfortunate trait and a trigger.
The trait is that not enough people are unwilling to criticise stupid arguments or points or ideas that are "on their side". Their side might be an actual sided conflict (with another group, perhaps) or it might be simply the vanity of some group identity.
The trigger is usually that somebody (or some small group of people) either knowingly or out of inflamed pride says something stupid or has a terrible idea.
So maybe this is yet another call for vigorous internal criticism, in a society, a movement, or any social group.