UGH. That's brutal. I have such mixed feelings on topics like these. On one hand, I think zoos and aquariums really give people the chance to appreciate amazing animals, a wonderful place to give an animal rehab and a life they may not have had in the wild, but on another hand, if not done right, it can be incredibly cruel.
I definitely think whales are WAY too large to be confined to swimming pools, no matter how big. They normally do not attack humans in the wild, so you have to ask yourself why it would happen, and the answer was most likely the confining environment, and people forgetting they are dealing with wild animals. It's sad all the way around.