Aliens being higher up on the food-chain and using us similarly to how we use use animals is perfectly consistent in nature and well-grounded, like it or not.
Most of us can't begin to imagine the cruelty we inflict on other animals in order for us to survive and compete. This movie illustrates what that cruelty might be like, then poses the question - how do we know this can't happen to us?
There is as overwhelming amount of cases where people remember being abducted, used, abused by aliens like in this movie to further their genetic goals.