Been flying for 25 years, 1.5 million miles total, most of that on United. US airlines have been through hell over the last 16 years. Bankruptcies, union battles, fierce competition, and not to mention, the real threat that someone could blow up or intentionally crash the plane they're flying, all contributed to a mentality that the employees have to stick together to survive.

The end result is that US airline employees see their loyalty to each other as more important than customer service.

This mentality enables the micro-selling, endless class stratification, rigid authority and the generally unpleasant demeanor of staff. They're really not friendly in the US, and strikingly different from, say, Asia-based carriers.