In what way is it different? I also rear guppies ,cherry shrimp,brine shrimp and daphnia as food, would you object to that? i also collect earthworms to feed to my axolotls and frogs. I provide a diet of live food to my pets in addition to a small amount of pellet food. My amphibians are predators and they get a varied diet, which i hope provides them a balanced source of nutrition. If you dont like feeding animals to other animals you might like to get a tortoise or a rabbit. You could make the argument that axolotls can survive on pellets and that live food is unnecessary and cruel but those pellets are made from animal protein(as far as i am aware).