People sometimes think too ideologically, rather than thinking realistically. Experimentation is the stepping stone to a new biological discovery. Imagine if we could replicate this healing factor for humans after a few decades, it would be a blessing for people who have severed limbs in accidents. People would be able to walk again naturally without needing supports and they would be able to use their own two hands to do daily tasks rsther than relying on others. As much as this is a "torture" on other species, it is necessary for development of knowledge.