We all (often deservedly) mock "security theater" and some of the more ridiculous rituals of the airport experience, but I don't doubt that there is some purpose to airport security. The prevention of hijackings and plane bombings seems to be an important goal, whether or not the way we go about it is precisely the right approach.
Throwing a bunch of untrained dickheads whose core function is harassment and violent kidnapping does not seem likely to improve the speed and efficiency of that!