Originally Posted by
gamevet
They created human (not clones) slaves that are genetically superior to their creators. Knowing that these super human beings could be a problem, they are prohibited from being on Earth and owning any sort of replicated creature is borderline illegal as well. The creators put a very short life-line on the replicants, to prevent them taking over, should they find a way to do so. And that's what set off the events that unfolded in the 1st movie and the 2nd movie appears to be about what the creators feared would happen.