A private company will hire experienced employees, unless the project is also intended to provide training. CHM projects are normally too complex, too time critical, and too budget-oriented to allow for much experimentation or on the job learning. If private companies do not keep up with the rapidly changing field of CHM they will either not get the project to begin with, or they will never get another project in the region, and ultimately go out of business all together. Private companies must be accountable to their client's best interests, which in this case is the protection of the borrower country's cultural resources. If they are not, they have no sinecure to fall back on.
Private companies have to produce or they are history.
Dam and reservoir projects are not confined to one season of the year, or even to one year. CHM projects may start during the academic year or require continuous full time work over a number of years. In this situation, academic institutions have difficulty consistently devoting adequate time and resources to a CHM project and to the other duties of academia, teaching and research. Private companies do nothing but CHM all year long. They are also used to hiring people on a project to project basis to be available for contracted projects.