They wanted to get the message out to everyone just how bad Serbia has been treated by their government. The imagery provides two purposes - it ensures people know about the film, and it serves as a brutal metaphor.
Nobody is forcing you to watch it, and nobody should stop someone from making it either.
There are far better ways to bring points across than depicting a scene where a fat guy rapes a newborn to death tbh. Like I said, my niggle isn't with the film but one scene, I just find it unnecessary.