In college, I got a part-time job for a stretch of some months grading exercises at the local Kumon center. The job consisted primarily of comparing a filled-out exercise booklet to a printed list of answers and marking incorrect answers. (The other part, the good part, was talking to the kids and trying to help them with problems they didn't get.)
My boss was never happy with the speed at which I worked. Eventually she told me I was too smart for the job and should aim higher. In a vaguely similar way, I don't think Wal-mart is looking for their lowest-level employees to make a lot of independent ethical decisions on the job. If you're going to be hiring unskilled labor, you might not want them to exercise a lot of discretion, on the theory that they're at least as likely as not to screw it up.
My boss was never happy with the speed at which I worked. Eventually she told me I was too smart for the job and should aim higher. In a vaguely similar way, I don't think Wal-mart is looking for their lowest-level employees to make a lot of independent ethical decisions on the job. If you're going to be hiring unskilled labor, you might not want them to exercise a lot of discretion, on the theory that they're at least as likely as not to screw it up.