The TSA issues two seperate credentials that require a fee, background checks, fingerprinting, and 5 year renewal requirement. One is the TWIC ($125/5 years and required for employment in certain transportation fields). The other is Flight Pre-check ($85/5 years and completely voluntary. It is, in essence, a convenience tax).
People who carry the TWIC have been vetted to enter MARSEC level one facilities, unescorted, throughout the country and have met the necessary requirements needed to qualify for flight pre-check. As a whole, the people who hold these endorsements travel frequently, aid and enhance the national transportation infrastructure of this country and should not be needlessly hindered nor financially burdened by the exhisting TSA flight screening process.