the fact is movies are
a product of the imagination
entertainment in this form
is the highest form of escapism for the masses
as a consequence
any knife which one sees on the silver screen
was placed there
purely for dramatic effect.
so that a bad guy in a movie
would always have a menacing looking knife.
or likewise for a hero,
who uses his intellectual capabilities more
would be holding a multitool or the likes.
i suppose there are people in the props department of any film production crew
who would have enough product knowledge
on what would evoke
the required emotional response for a required film's scene.
....I think that makes sense
