An article I found pointed out the probable root cause -- the TSA is now refusing to staff exits from secure areas, claiming that they are only responsible for

An article I found pointed out the probable root cause -- the TSA is now refusing to staff exits from secure areas, claiming that they are only responsible for screening. That puts the burden for exit monitoring onto the airport operators. Naturally, this cost falls disproportionately on smaller airports where the volume of passengers over which to amortize the cost is less.