A company can become broadly hated if it alienates a large enough group of people. It may frustrate customers with poor service, anger employees with unpleasant working conditions or low pay, and fail shareholders with poor returns. Often, these shortcomings are intertwined and it’s usually enough for a company to antagonize one of these groups for its reputation — and even its operations and finances — to suffer. Many of the most-hated companies have millions of customers and hundreds of thousands of workers. With this kind of reach, it’s important to keep employees happy in order to maintain decent customer...