Chins living in building with no a/c or heat depends on the climate. I know many of the ranchers in South America ( perhaps all of them?) do not heat or cool. I can't verify the climate in those areas, but I know that on the pelt market South America is kicking our butts on quality, same in pelt shows, and if it was economical for them to bring live animals, I'm sure they'd be doing it in the live animal shows too.
Everything is relative. Know your animals, know their limits, and know your environment.
Chapman brought chins here less than 100 years ago... there are people who are still alive that were alive when that happened. Are they wild? No, but like wise they haven't been domesticated for centuries. If you figure a chin lives 20 years, that is only 5 generations removed from a wild chin. Comparing a shih tzu to a wolf is not even relevant. In 5 generations you can not go from a shih tzu to a wolf using selective breeding.
And lastly, the person who post pics of the difference in wild chins from domestic chins, you are ill advised. Wild chins look JUST like domestic chins, taking photos off people's online photo albums is not the ideal way to try to prove a point as that is not a wild chin.
http://www.wildchinchillas.org/
My point of view is know your animals, know your environment, know their limits. A zoo is not a pet education center. People keep monkey's as pets, but do they go to the zoo expecting to learn how to care for them? No. People keep parrots as pets, but again they do not go to the zoo expecting to learn how to care for them. If you are expecting the zoo to teach people how to care for chins as pets, you just as well tell them to get a FN and fill it full of hammocks and huts.
Am I saying zoos should keep their chins outside come **** or high water... I didn't say either way what I think, but I think that it's only ideal for people to know more facts before making decisions.