I would argue that having screeners on TSA payroll has benefits for when things do go wrong. For one, there's at least accountability of a governmental nature. Private contractors don't have to publish rulemaking notices in the Federal Register or respond to FOIA requests. The government does. You get to elect the people who have ultimate control over the DHS payroll...you do not get to elect the Wackenhut CEO. If you want a good example of how lack of accountability to the public can cause big problems, go back and read about the Washington Metro Transit PD's crusade against french fries and talking loudly.
I respectfully disagree. The issue is that there's no accountability. The TSA talking heads, who officially speak for the Director, routinely blow off the taxpayers. There are countless examples of this. The TSA responds to FOIA requests by not responding to them. The only thing the FOIA law states is that an agency has a specific period of time to respond that they received your FOIA request. They are under absolutely no obligation to anyone to ever respond. The only oversight that occurs is an agency head who makes it a priority to respond to the taxpayers -- their customers, by the way.
The TSA grew out of the FAA Office of Civil Aviation Security. After my retirement from the USAF in 1998, I interviewed for several senior positions in the FAA, including the deputy director position in the Civil Aviation Security office. (Thank God I wasn't selected!!!) I had a senior VP from one of the FAA's major contractors tell me that it's the FAA's style to "hunker down and retreat" (his words) when public criticism comes their way. Substitute "TSA" for "FAA" and it's very easy to see that the culture remains intact. Face it: The TSA is like the old Soviet Politburo. The main reason for their existence is to perpetuate their existence.
Wackenhut was doing just fine on 9/11/01. A whole lot of US Government counterterrorism things failed LONG before 19 terrorists passed through airport checkpoints.