And that's where they're wrong. An animal in captivity is not in the wild so they don't act the same.
The only agenda zoos and circuses have is their wallets.
They can say what they want but it's all about the money.
They've had plenty of time to do research.
What more do we need to know?
And people need to keep their kids on a tighter leash. I bet if little Johnny had been disciplined right earlier in his life we wouldn't even be having this talk. Too many prizes for just participating not enough swats.
In general yes zoos are pretty abysmal, but the thing that hasn't been mentioned so far is having a healthy gene pool. As it stands many critically endangered species have such small populations left in the wild that inbreeding and negative genetic mutations are a major concern which can push breeding groups/pairs etc into further decline. As sad as it is, having viable breeding populations in captivity actually gives a little more hope that numbers can be increased and reintroduced into either existing ranges, or sometimes new viable areas for population. Depends what the underlying causes of extinction threat is, and whether human intervention can feasibly make a difference to stabilise and increase numbers.
There is almost always more research that can be done and more information carried out on any species - most of the valuable, accurate research about dietary requirements and habitual behaviours is relatively recent in the grand scheme of things. That's often the most important knowledge in understanding population decline where the obvious factors like poaching or habitat loss aren't the main contributing factor.
Take the Giant panda for example... you rarely hear people complaining about pandas being kept in captivity and bred because without human intervention they'd probably be long gone by now.
Places like Seaworld can go suck a f**k though. Keeping a whale in a fish tank is like locking someone in a closet and beating them with a stick until they consent to you beating them with a bat.