Replicants in the Blade Runner world are generally slaves. Especially the four who are on the run trying to just live.
With that said, Batty, the ring leader, likes to talk heady. Kowalski is represented a little dumb, literally supposed to be the muscle of the group. He is likely only repeating the things he heard: things Batty said to him to convince him to run, to find Tyrell, to find a cure.
Deckard is literally hunting down run away slaves with a dated kill switch, with the plan to kill them. Given the situation, and that Blade Runner is a Noir detective film its unsurprising the characters all talk about death and running in fear, its the theme of the movie.
Heady and repeated speeches are the norm.