I think this whale's kill record has been somewhat exaggerated. The second kill was a mentally unstable guy who trespassed, jumped in the tank naked and then died of exposure. The whale was swimming around with the guy draped over its schnozz. Hardly a kill, but more like playing with its new big human toy. Overall this is a big playful cute killer whale that just wants to play.
Me, I like zoos. I like Sea World. Animals in captivity are un-natural, but lots of things aren't, like Twinkies. The deficient thinking part of this lies in the now-dead "trainer." The news reports indicated she was very experienced and had been working with these creatures for 16 years. I would say that the training curve estimate lies now beyond 17 years. I think this is a tragedy, but when you work around things that can kill you, like killer whales and kitchen remodel job sites, sh!t happens. Safety is job #1, and you always have to be careful. She sadly wasn't.
I think that the other handlers there may be very uneasy about doing a show with that one now. Letting it go may be just as dangerous. It has been eating fish out of people's hands for years. It may think that people at a beach in Florida are fun toys and the only way to have lunch. Not good.