Of course there are plenty of examples of bad employees giving lousy customer service. But trying to solve this by declaring the customer “always right” is counter-productive.

Instead of finding assembly lines of productive workers, they quickly discover that their product is produced by utterly unpredictable, uncooperative, disobedient, and worst of all, unattractive people who resist all attempts at management.

The people you choose to work with are the most accurate predictor of job satisfaction I've ever found. And job satisfaction, based on my work experience to date, correlates perfectly with success. I have never seen a happy, healthy, gelled, socially functional software development team fail. It's a shame such teams are so rare.