Something really rubs me the wrong way about paying the government to mistreat me less. It really seems to me like it was created to make sure that wealthy, and therefore politically influential travelers don't get too upset about the TSA and demand reform.
I don't think it's necessarily intended to discriminate by income, but I do think the intent is to avoid political pressure to back off on general screening procedures.
Most people don't have TSA precheck because they don't fly enough to bother doing it or don't know anything about it so don't research it further.
If you are rich you're flying in business/first class or have elite airline status as it is, so you'll get priority screening regardless of whether you have precheck or not. If anything the biggest cheerleaders for TSA precheck are the airlines because speedier security means fewer people missing their flight due to long security lines.
Priority lines gets you a shorter line. Precheck gets you a less invasive screening procedure.
Priority lines exist because the airport, rather than the TSA controls the lines. The airport tries to do what the airlines want, and the airlines want people who pay them extra to have a better experience. This is arguably broken, but it's not really the TSA's fault.
