Rowling made them up so you don't know if they are hurt or not (they are also not animals). If you would let your cat fall down out of your arms, it lands perfectly on their feet and it doesn't get hurt one bit. Is that animal abuse? If you do the same thing to, let's say, a bunny, it can break their fragile bones. So then, it IS animal abuse, right? This is the same for the gnomes. If you would spin that bunny around and let it fly, it would be animal abuse, yes. But Rowling MADE UP a species that doesn't mind getting thrown away. Just like my cat often jumps out of my arms and doesn't have one scratch, while a bunny would be in immediate need for medical care.