This is my experience as well. These private companies are drawing from a pool of people who are willing to do a wretched job for not very much money, so it's not surprising that they'd be largely indistinguishable from federal employees. Too, it's not the TSA employees who are the fundamental problem; it's the organization as a whole.
I disagree. Having travelled extensively and been used to elevated threat levels throughout most of my life, I can attest to the fact that the average retail TSA employee is about as backwards, disorganized and inept as one could expect from the day-labor source pool.