I can speak only from personal experience, I own several parrots.
The positive is that exotic pets are a real conversation piece. And other people are generally interested in something out of the ordinary. The more you learn about your pet, the more you can inform others. A side benefit is that you can counsel someone who may be thinking of acquiring one of these animals, if you see that they are really not suited for the responsibility. Another plus, in the case of parrots anyway, is that they are very good company. And very amusing. They enjoy a good conversation, and will often take part, or start one of their own. Of course, you cannot force one to contribute at your command, but when comfortable in their surroundings they will often carry on to the delight of all. With parrots in my home I have never felt lonely. And never wanted for a compliment or a laugh.
The downside is multifaceted. First, some of the exotic animals have very long lives, and therefore acquiring one is a very long commitment. Lifestyles change, often eliminating the accommodations that the exotic pet needs for optimal care. Finding a suitable home for an exotic that you can no longer care for is difficult. Every pet requires periodic veterinary care, and finding an exotic animal vet is not as easy as finding a regular dog/cat vet. The regular vets don't necessarily have the training or education to deal with the specific problems of the exotic pet. Providing the appropriate feed for an exotic may be more time consuming (going to a special store) or more expensive. Finding pet-sitting service is much more difficult than asking a neighbor to feed your cat while you go somewhere for a weekend. The exotic animal has specific needs that must be met on a regular/daily basis, and there are few who understand the needs well enough to be trusted with their care. I have had to train each person who was willing to take care of my pets while I was away. And I still worried over the one bit of information that I may have forgotten to instruct my sitter to be aware of. I have developed a list of responsibilities to cover, and present the list to each person I hire to watch my home while I am away. And, then finally, one thing I've noticed is that the average house guest does not have the common sense to know how to behave around an unusual animal. I'm constantly monitoring their behavior, for their own protection as well as the protection of my pet. Often well-meaning guests will reach their hand out toward a bird who could break their finger faster than I could prevent it. Equally distressing is that a guest will unwittingly make a gesture that is perceived as threatening to my bird, and I have to simultaneously deal with the stress of the pet and the ignorance (lack of knowledge, not stupidity) of my guest. Another risk is that people for some reason feel free to offer food to my pets. What they don't know is that several common human food items are considered toxic to the exotic birds. So there is the constant vigilance of protecting the pet from the innocent gestures of strangers.
To add to the astute observations of the previous commentator: To me, the downside of exotic pets is so overwhelming that I can't justify having one. Consider the fact that the state of Florida now has breeding populations, in the wild, of constrictor-type snakes like boas and pythons. These reptiles grow big enough to kill and eat dogs, raccoons, cats..even children. Consider the small but significant number of people who knowingly purchase snakes that are venomous to a high degree for pets, and are killed by them. Consider the fool who made the news not so long ago because the tiger he kept IN HIS APARTMENT killed him. And the list goes on. Unlike the parrot owner above, enough people who acquire exotic and sometimes dangerous pets are not responsible enough to own a dog, and end up dead. I don't recall the details, but there was a woman bitten by her baby Gabon Viper. She left a note asking the authorities not to hurt the pretty little baby snake that had killed her. Or the man who, bitten by his pet cobra, went to the bar below his apartment to have a beer while awaiting the ambulance. He died in the bar. Nutria are another example. They've changed the face of nature in some southern states by breeding in huge numbers, overpowering some domestic species, and altering the ecology permanently. In Florida, again, there are flocks of wild parrots, formed from the descendants of pets that someone thoughtlessly released, or allowed to escape. They are a nuisance in some parts of the state. Or, check out the people who pay $25 for a beautiful Blue Ringer octopus from Australia. These gorgeous creatures, though no more than 3 inches long, can bite through a rubber wet suit. Once bitten, unless CPR is administered for 12 hours or so..the victim dies, fully conscious but paralyzed and unable to move. I like animals a lot, and have always had a pet. But none of them have been a threat to me, my family or friends, and none of them had the potential to disrupt the ecology of the area I live in. To me, it seems logical to enact and enforce a moratorium on the private ownership of exotics that pose a threat to people or the environment. The fun of having an unusual pet does not, to me, outweigh the personal danger and possible environmental disasters that can occur when such a pet is kept by a fool. Let the zoos and other accredited organizations do as they like..they are liable, and have the education and resources to deal with them. Otherwise, it seems to me that the possible negative effects are much too great to make the ownership of such a critter worth the risk.
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I remember "Quack", a Mexican Red-Head, we called that variety then. He was surely kidnapped as a baby from the wild. He must have been interned on a farm in Mexico before coming to Miami in the late sixties. He only made barnyard animal sounds. Wonderful friend. He had a life that perhaps he would not have had in the wild. I took him outdoors for bike rides on the bars and flying lessons, and we were best of pals. Exotic pets can be good for us and we can be good for them. We had an Australian Shingle back skink...for twenty-one years, and he was happy here. Returned him at last to the exotic animal dealer who provided him in the first place. Exotic animals need exotic care. Lately, am very fond of our bufo toads in our garden. Our outdoor cat does not like them, though, as they usurp the cat's food. Animals love people, given a chance...