If you didn't feel empathy for the replicants getting murdered in the movie, and instead just thought of them as robots getting retired, then you're the true replicant. They say repeatedly that they live in constant fear of being hunted at all times. They are slaves with nothing of their own, not even their own memories, and a brutally short lifespan. It was Tyrell's fault for making them as close to humans as possible in this manner. No real human would ever be ok with living in those conditions. At the end, Deckard's journey concludes with him going from uncaring and disgusted by them, to understanding and empathizing with them. He sees that they greatly value life and want to live more than himself and many real humans do. He sees how they cherish photographs, memories, and being remembered by others since their entire existence is so fucked up. And Deckard sees how finding out the truth devastated Rachel and made him care about her instead of just blasting a malfunctioning 'it' as usual.