We adopted three kittens that were found locked into a suitcase and thrown into the trash. Our house is in hills with coyotes so these cats would not survive for any length of time outside. They'd probably also be sent to the pound if we didn't adopt them. I feel bad for confining them in our house but I don't know if there would have been a better outcome for them.
Totally agree on more rare/exotic animals though - they shouldn't be subject to unnatural conditions like this.