No, because research and discovery could be a passion for some and a PhD could be a fulfilling experience. PhD holders can pursue post-doctoral research positions which can provide them with in-depth knowledge of their area of interest.
Yes, because there have been a surplus of PhD candidate leading to competition for limited positions in academia and industry. With less opportunity in their area of interest, the PhD holders may seek their way outside their field thereby not utilizing the knowledge gained during their training as a PhD student. Moreover, when there is a surplus of PhD degree holders, the chance of getting a good salary package is reduced.