It may also significantly delay departures if passengers delay their transit to the gate to say goodbye to friends, relatives, etc.
I agree that security is, in many instances, becoming too reactive and often lacks focus. I say that having been on the receiving end of some truly ridiculous, bureaucratic, and inconsistent security regulations whilst in full uniform and displaying a valid airline ID.
Still, that's life now I guess. I sometimes wonder who's winning the war against terror.