Why are people not aloud wild pets?

because in all fairness isn't every animal wild, or were at some point especially dogs, you get wild dogs all over so why is it not aloud to have a wild pet , given the proper facilities yes in this day and age so. if say two monkeys or loris' grew up as a pet and another of different , if they were too mate then maybe it might cut down on the "wild instincts" and be able to become a pet. how did it all start with dogs and cats!!??