The TSA's "faux" law enforcement style impairs their ability to have a service culture. They're dressed as fake cops, and call themselves "officer." They've built this artificial authority that is particularly ripe for abuse.
Although security can be onerous in other countries, the European security personnel wear normal clothes and no badges. In Israel, they wear khakis and white shirts. No badges. The attitude is, "I'm here because I work in airport security." The TSA's image, is "I'm so friggin' important. You will respect me."
The service/client issue becomes more complex if one considers a class issue. The TSA's employees are generally blue collar. Although they have some who are college-educated, others have had meaningful military and law enforcement careers--but I don't think that's the norm.
The flying public is overall wealthy. Frequent flyers are generally well-off. We travel in first class, stay in nice hotels, and have more meaningful jobs than counting the ounces in a shampoo container.
From an organizational behavior standpoint, we have blue collar workers, dressed as authority figures, asked to conduct humiliating searches on those who lead a life of greater privilege. This can't be good.
A compassionate viewpoint would say, "look at the screener." He or she has to spend long hours at a checkpoint with pitiful leadership, inane rules, and an endless sea of angry, tired passengers. He or she gets an acceptable, but not great paycheck.
Meanwhile, you are standing there, holding an "Gold/Chairman's/Platinum/FancyPants" frequent flyer card with a first class ticket to Maui. The only control that the screener has is to bark, perform a "continuous screening secondary," or look at you naked.
Of course I'd like to say, "Get a more meaningful job. You'll sleep better at night." But from a systems standpoint, I would like the TSA to be more focused on being helpful. They could take the attitude, "I'm here because I care about you and your family, and keeping the plane safe is my job." In other words, it takes the job of a TSA employee into a "helping" role, not a "controlling" role.
The other aspect from a systems approach is to eliminate opportunities for petty power trips. Harsh penalties for barking. Stop the liquid and shoe business. End the "stare downs." Use full body x-ray only when you must, and only with the passenger's informed consent.