It parallels the thought process behind different strains of the same species being relocated to another region. For example, Florida bass won't survive in Indiana. Some intergrade cross might, but then the native genetic strains become compromised. The state of Florida won't allow northern strain largemouth to be stocked south of the Suwanee River. We don't want Coppernose bluegill stocked in Kansas. They die when cold. Same with smallmouth bass. There is certainly a financial incentive that runs parallel to the conservation/stewardship thoughts. Why stock a northern strain of Smallmouth bass, native to Canada and Great Lakes States into water in Missouri? You don't. Job One is understanding there are different strains of the same species of fish and then figuring out which one is best suited (or not) to the region you choose to supply as a responsible hatchery owner.