because they have good protection. Nowodays, a lot of animals live in zoos. And it is not the animal to be fault. Secondly, animals have good life conditions in zoos. The animals are forced to live in a unnatural habitat. Domesticated Devils have not had this caner problem.
The amount of possibilities of them dying, shot by hunters or any other reason, still higher than the chances of their survival. Its like being taken off the street as a hobo and living in a luxurious suite, fed meals every day, bathed, regular doctor visits to make sure you're in good shape. Some people agree that animals should be kept in the zoo. Or would it attack you! Animals live as close to the natural habitat as possible.