TSA is a manifestation of the totalizing technocratic State and all that that implies. The motivations are manifold and they evolve and are discovered over time; I wouldn't argue that there is only one reason. Being also a 'jobs program' in no way invalidates my point.
By the way, shepherds don't scare sheep, wolves do. Shepherds corral sheep. Sheepdogs harass sheep, triggering their herd instincts by raising the specter of the wolf in their minds. Sheepdogs are used by shepherds in order to herd sheep to where the shepherd wants them 'for their own protection' and his use.
But to make the point less metaphorically, the intention isn't to scare people, but the effect is to herd people efficiently, by reassuring them through fear. The fear we feel when we have our hands in the air like criminals to be screened is transferred to the fear we assume those who would harm us must feel and we assume the deterrent affects them, too. The dog that nips our heels will surely chase off the wolf. That effect (efficient management) is itself desirable and so the preservation of that effect becomes another motivation of the system.
By the way, shepherds don't scare sheep, wolves do. Shepherds corral sheep. Sheepdogs harass sheep, triggering their herd instincts by raising the specter of the wolf in their minds. Sheepdogs are used by shepherds in order to herd sheep to where the shepherd wants them 'for their own protection' and his use.
But to make the point less metaphorically, the intention isn't to scare people, but the effect is to herd people efficiently, by reassuring them through fear. The fear we feel when we have our hands in the air like criminals to be screened is transferred to the fear we assume those who would harm us must feel and we assume the deterrent affects them, too. The dog that nips our heels will surely chase off the wolf. That effect (efficient management) is itself desirable and so the preservation of that effect becomes another motivation of the system.