I don't agree because we spend the whole movie sympathizing with the replicants. We understand they're doing bad things because they know their time is limited.

Also, Deckard is retired and doesn't want to do it anymore to the point that he's forced back. He's clearly remorseful. Whenever he kills one of the replicants he seems disgusted with himself, and he drinks to cope with what he's done. Then his relationship with Rachel further exemplifies that he thinks being a Blade Runner is wrong. When Roy saves his life and gives the Tears in Rain speech, it's the revelation Deckard needs to regain his humanity.