Homo sapiens generally likes being at the top of the food chain. In some natural settings we are not—think about going one-on-one with a crocodile or a grizzly—but in the civilized world we rule.
Not every creature is designed to be at or even near the top of a food chain. Some critters are prey animals. Deer are an example, and when deer move into an environment with no predators, their population will explode until they overgraze the area, destroy its ecology, and then die of starvation. A healthy deer population requires predation.
Of course, the idea that culling a deer herd is a good thing offends that special group of humaniacs called bambiists. A group of them is now protesting a National Park Service hunt in Rock Creek Park in DC. (WaPo story here.) They think that the deer can be put on birth control.
No, what works is predation. The practical choices are hunters, wolves, or mountain lions. Considering that the hunters can be expected to limit their predation to the deer, they strike me as the best choice for an urban environment such as DC.
BTW, a deer ate that crocus I photographed yesterday.