Most animals that are admitted into rehab require help due to human impact. A car hit the mother, a fence caused serious injuries, hunting (both legal and poaching) kill a female or industry caused separation of a family.
Rehabilitation offers a opportunity to minimize our human footprint. It gives the injured and/or orphaned animal a chance to return to the wild and be part of the natural population.
Rehab also provides care for an animal in need and can support scientific studies that support the species.