Costco hasn't been sued for employee abuse too often (see: overtime), they don't put people out of a job by *forcing* companies to maintain prices that are lower break even (see: rubbermaid), and I've never heard of them shuttign stores down because the workers unionized (see: union).
Wal-Mart is considered evil because they only work in the interest of putting money into the pockets of Sam Walton's kids, and they don't care how many lives they destroy to do it.
Overtime
http://www.washingtonpost.com/wp-dyn/content/article/2006/10/12/AR2006101201608.html
Rubbermaid
http://www.washingtonpost.com/wp-dyn/content/article/2006/10/12/AR2006101201608.html
Union:
http://money.cnn.com/2005/02/09/news/international/walmart_canada/
You do not have the right to never be offended.
