Scott didn't make a film slavishly devoted to Dick's intentions. By any reasonable metric, Scott did a piss-poor job of adapting Sheep
- if one's intention is to be faithful to the source material. Where's the police station full of replicants? The pet goat that Deckard wants as a pet - and in fact is the reason he takes the job, so he can afford to buy it? Gone. Rachel killing the goat? Gone. His wife, or the mood organ? Gone. The need for offworld emigration (radiation left over from WWIII, or World War Terminus as it's called in the book) isn't discussed at all
. Sure, we see the blimps and hear the advertisements, but they don't say why people need to leave Earth.