I used to work at KATL, and ramp workers would get hired, work for 2 weeks until their background checks came back, then get fired because they were convicted felons who lied about it on their applications. (One enterprising soul drove a tug off airport and tried to pawn it!)
As long as security/ramp service/ catering/ cleaning is a minimum wage job, you gets what you pays for. Security should not be determined by the free market!