This is typical modern Bloomberg reporting - telling a misleading, emotion driven story from anecdotal data and rumors.

"The Amex people, most of whom had MBAs, sometimes found it amusing to deal with Costco veterans who spoke about starting out stocking warehouse shelves. Less endearing was the habit Costco executives had of referring to Amex as a “vendor.” That made the Amex people seethe. After all, they represented one of America’s oldest corporations. But they smiled and said nothing, and the corporate marriage endured for 16 years."

Seriously?