The term is used to emphasize the fact that many desirable middle-class jobs are being eliminated, either due to productivity gains (often the result of automation) or due to the shifting of operations to second- or third-world countries where labor costs are cheaper. For example, manufacturing, call-center, accounting, and computer programming jobs are not as abundant in developed countries, as they used to be, as firms have looked abroad to meet these needs, frustrating many people who used to work in these industries. These displaced workers often spent many years gaining specialized education, training, and experience, and don't want to start over at the bottom rung in a new industry. However, many older workers may have no choice but to take a "McJob", because an employer will prefer to hire a younger person who has just finished college for an entry level job.
According to Jim Cantalupo, CEO of McDonald's, the perception of fast-food work being boring and mindless is inaccurate, and over 1,000 of the men and women who now own McDonald's franchises started life in the working world behind the counter serving customers.