Deckard is the audiences entry point and point of view to the story, it starts with a jaded cop hunting machines. But as the story moves it is revealed to the audiance that the machines have a humanity while Dekard's journey takes him to accepting their humanity and recognising his own inhumanity. It the journey the audience goes so "untwisting" it 30 odd years later may jar many. Its a bit "it was just a dream now but the new film".
The whole film is suffused with the alienation, dislocation and loss of identity in a megacity. At the time perhaps playing on fears of over population, now it may pull more to fears of multiculturalism. The crowds, masses of languages and alieness of it all while the white, clean upper layers were riddled with nostalgia for the 50s, in part set by the film noir lighting and tone. Deckards journey from a alienated soul in the swarm of humanity to a plot resolution of him finding a place where he belonged even if it was one soon to be dead android worked. Well in my daft opinion.
