Let's compare some workplace statistics, as reported by the companies...
Employees covered by company health insurance
Insurance-enrollment waiting periods (for part-time workers)
Costco 6 months
Wal-Mart 2 years
Portion of health-care premium paid by company
Annual worker turnover rate
Read more about this here.
The Wal-Mart people need to go read Doug Smith's On Value and Values.
Why does Wal-Mart want this? This is not a PR problem, Wal-Mart. It's a values problem. Again, read Doug Smith.