Every airline has its horror stories, of course—air travel is full of opportunities for customer disenchantment. But United has proved an industry leader: On all major performance metrics—delays, cancellations, mishandled bags, and bumped passengers—United has, since 2012, been reliably the worst or near worst among its competitors. In 2012, according to the U.S. Department of Transportation, United was responsible for 43 percent of all consumer complaints filed against U.S. airlines. It finished last among North American nondiscount airlines in the 2015 J.D. Power & Associates customer satisfaction survey. ... It’s been five years since United Airlines and Continental Airlines combined to form what was at the time the world’s largest carrier, and the merger hasn’t gone well. In 2012 and early 2014, when American Airlines Group, Delta Air Lines, and Southwest Airlines reported large, and in some cases, record profits, “the new United” lost money. ... Then there was the coffee, an issue that, while hardly central to its business, symbolized United’s inability to get things right. On Nov. 19 the airline announced it was changing the coffee it serves on its planes and in its lounges from a brand called Fresh Brew to the Italian premium roaster Illy. It was welcome news to customers and to the flight crews used to fielding complaints. It was also a tacit admission that the choice of coffee after the merger, a decision that consumed thousands of man-hours, took nearly a year, and involved everyone from Smisek to the airline’s head chef to the flight attendants, hadn’t worked out.