Oh come on! Blade Runner makes no sense. The whole Deckard-replicant thing was tacked on at the last moment and has absolutely no logic to it. Once you actually think about how it could be possible and the implications it raises the entire idea falls apart. Whatever answers you provide on your own are inevitably reaching and would be considered unrealistic and implausible in any other movie. In fact, most of the plot is utterly implausible, starting with the year 2019 and on through just about every element in the story. There are holes in that script big enough to pilot a spinner through. Plus the characters are rather thin and the acting is a bit stiff. Why do you think so many hated it in 1982?

But it's brilliant. It's brilliant because it's not about the plot or the characters in the sense of traditional drama, it's about ideas, philosophy, visuals, atmosphere and creating a world. That's why Blade Runner has any merit to it, and that's why it was misunderstood, because people thought the film was about detective Han Solo chasing robots in a trenchcoat. Go read the negative 1982 reviews of Blade Runner and you will be able to substitue the word "Prometheus" and magically end up with the same reviews as 2012. It's fitting since Scott admits that Prometheus is more a spiritual sequel to BR than Alien, since it deals with the same themes and ideas.