Fox 8 points out in their investigation that North Carolina rejects funding that would put children permanently with relatives instead of in foster homes. Grandparents who are able and willing to care for their grandchildren, for example, are routinely rejected by the State.
Melissa Painter of Fox 8 points out that in North Carolina more than 10,000 children are in foster care under the care of the State. This brings in more than $198 million of funding to take care of these children.
Federal laws actually require States to give preference to placing children with relatives. There is even federal funding available to place the children with relatives in "permanent legal guardianships." But North Carolina (and many other states) do not follow this practice, because children put up for adoption bring in more federal funding. Instead of giving federal funds that can be designated for relatives in guardianships, they keep the funds for themselves to administer the foster care and adoption system.
In short, a child put into the foster care system on the path to adoption, brings in more money to the State, and employs more people to "administer" these children.