Is it the recruitment process or the training of these "screeners"?
Not having been to the USA recently, and thus having no personal experience, and relying on the various postings here - it seems that these people lack not only basic education and commonsense, but have abslolutely no knowledge of the real world.
And the question then arises: what is the point in having them?
I know - window dressing to satisfy the travelling public. Maybe the travelling public is part of the problem. If they're that easily satisfied good luck to them.