Path departments have a financial incentive to maximize residency spots. Would they rather pay $100,000 for a pathology assistant, or would they rather get free pathology resident grossing labor. Not only is the pathology grossing labor free, they get a large sum of money to 'train' the residents from the federal government. In some programs, 'training' consists of spending a substantial portion of time grossing small biopsies.
I don't buy the argument that pathology departments lose money in the long run by having residents, because they need to spend time 'teaching' them. In many programs, besides the occassional lecture that the faculty has to give, a lot of the 'teaching' consists of signing out with resident at the microscope, with the resident acting as a scribe. If anything, it frees up more attending time.
Anyway, the end result is a surplus of graduating residents.
I think a lot of patholgoy residents end up not speaking out about these things, since a good portion are foreign medical graduates who probably don't know any better.