Originally Posted by
t hedge coke
Slashers tend to work by fear/surprise/emotion more than by narrative logic. What's important is not causal logic, but how it makes the audience feel in the moment.
Leatherface dances, has fits, gets distracted in the original Texas Chainsaw Massacre simply because otherwise the actor was too fast for his fleeing costar. Now, there, it adds character, because he's insanely fast when it's good and shocking and he's lackadaisical when that's more plot-servicey and visually entertaining. Other times it's not as rewarding.
For almost every Halloween movie, what's important about Michael Meyers is that he's the bogeyman and he doesn't really make sense. That whole driving around thing in the first movie, barely noticeable sometimes because his mask blends so well, the pranks and art installations he makes. Michael just does stuff because it's good for us, the audience. A later film tries to explain it all with some cod-Norse silliness that doesn't stick, and the first Rob Zombie film tries to humanize him and make Loomis' "he's the devil" stuff look silly and self-serving, but the second one goes back to Michael as the bogeyman, almost literally there.
It's the same reason most people in action movies die the second a bullet touches them, quietly and with little rupture to their body. That doesn't happen in life, it's not causally sound. But it's good for the audience, because otherwise, those giant shoot-em ups would be brutal as hell and no amount of one-liners could make it "all ok."
Causality takes a backseat in most genres.