Picker and c-ret jobs require being on one's feet, on concrete floors, during 10-hour work days. Hard work for pretty low salaries: $11.25/hour to start, increasing only a couple more dollars per hour in the next two years, then capped.
New-hire training does not accurately convey how keeping one's jib depends on meeting critical and difficult performance quotas.
New-hire training also does not accurately teach how the job is really done on the floor. Until one learns "the tricks", performance quotas are very difficult to meet. The tricks can only be learned from other people on the floor.
The company officially discourages cheating practices used by many people to exceed quotas. But the company also rewards people who cheat.