According to sinclair, why are the waste barrels not cleaned more often?

The correct answer is : Under the system of rigid economy which the packers enforced, there were some jobs that it only paid to do once in a long time, and among these was the cleaning out of the waste barrels. Every spring they did it; and in the barrels would be dirt and rust and old nails and stale water and cartload after cartload of it would be taken up and dumped into the hoppers with fresh meat, and sent out to the public's breakfast.