They were not androids there were replicats. They were fast grown "improved" humans. Otherwise you could just have gone, "Hangon, your made of metal".
It was a story about how we were persecuting and enslaveing another group of humanity.
His confusion may have been due to Blade Runner being loosely based on the book 'Do Androids Dream of Electric Sheep' by Philip K. Dick, which has the word android in the title. Easy mistake to make if you ask me. It was a story about how we were persecuting and enslaveing another group of humanity.