Have you heard of Messi, the puma kept as a pet in Russia? The couple who adopted Messi did so in order to save the big cat's life. The zoo that housed Messi could not take care of the cat's many health problems, so when the couple, who fell in love with the animal, offered to buy the cat to keep as a pet, they were allowed to do so.
In most cases, I'd be against big cats as pets, but in this case with an animal who needs special medical care, maybe it's not a bad thing. Nothing exists in absolutes, right? The cat certainly seems happy on his Instagram.
Some people keep smaller exotic cats as pets as well, such as bobcats and servals. I'm not sure how I feel about that, either. Is it really necessary? Obviously we've domesticated other wild creatures in the past, but cats are the creatures who domesticated US. What do you think of keeping big cats as pets?