Poppycock. I could make the exact inverse argument. Perhaps animals being easy to access in a city makes people care less about them. "Who cares if it goes extinct in the wild, I can still see it at the zoo." Without any kind of practical evidence, you cannot know what effect zoos have. The only effect zoos have had on me is that I went to a local aquarium one time and saw a giant sea turtle swimming round a very small tank. The sheer cruelty of that stays with me. A creature which migrates thousands of miles in nature confined to a cage perhaps ten meters long. It is, without a doubt, one of the saddest things I've ever witnessed. I don't think anyone who can tolerate zoos actually cares about animals.