The history of human/animal relations (no, not like that) is one of constantly recognizing that we do better when they do better. I've been reading zoo histories and it's astonishing how quickly things have changed and how quickly they continue to change. While the "I don't want to be wrong" response is there, the thing to remember is that zoos are places for scientific research and when the evidence suggests something can be improved, it often is.

Also, because zookeeping is physically demanding work, the generational improvements are faster than in, say, Physics. It's a lot easier for the next wave of young zookeepers to implement their ideas when the previous one retires to administration - especially if they have scientific data to back up their recommendations.