Really? Have you been to Wild Arctic? That walrus that swims in circles without fail every single time you visit, that is really depressing. The tiny polar bear exhibit with the pacing back and forth is not much better. The penguins, sharks, etc. I think are fine, though.
I am not 100% opposed to animal exhibits, I just think they should be very large and very well made (no concrete floors and small cages for land animals). They should be at a minimum like the Serengeti Plain at BGT or some of those at Animal Kingdom.