There are good reasons for these laws. Raptors play important roles in the environment. Bald eagles, like Franklin, eat almost exclusively fish. And typically they dine on dead, dying and weak fish. That television footage of the eagle swooping down to take a healthy fish out of a river or lake is the rare exception.
Humans benefit from raptors' eating habits.
As eagles eat fish, they also eat whatever the fish has eaten. If the fish has eaten a megadose of some toxic substance, the eagle will reflect this. Learning about the environment from the health of eagles helps people protect the planet for all of us. It means that there is value in having many different components to the life in a given area. The more components we have, the more stable the ecosystem we have.