I figured it was a PR thing. After a bunch of abuse/mistreatment scandals, the TSA noticed that willingness to complain about poor treatment was strongly correl

I figured it was a PR thing. After a bunch of abuse/mistreatment scandals, the TSA noticed that willingness to complain about poor treatment was strongly correlated with wealth. Paid pre-check lets them easily weed out the people who would actually make a fuss, while continuing to abuse the people who they know will just sigh and keep their heads down.