It isn't, but changes that require additional staffing simply aren't going to be tolerated. If you add more staff, that directly translates to higher ticket prices because passengers directly pay for most of the TSA costs. If you expand facilities, that takes away from the valuable real estate the airport would rather use to sell you magazines and duty free. It also harms their Clear revenue stream, who pays airports to make security lines worse as a means to convince people to sign up.