The Uncanny Absence of Idioms in Subtitles

I've never translated anything except the most basic sentences from foreign language textbooks, so I can't totally sympathize with their conundrum, but I feel for those tasked with writing subtitles for foreign films. I think a big reason why foreign films are often considered aloof or incomprehensible has to do with the crevasse between the words as heard uttered from the actors' mouths and the words as read on the screen. There's a lot of alienation going on there and it is reasonable that it puts off most people.

The weirdest thing, though, for even experienced subtitle readers (anime, foreign films, very-very-quiet screenings) is the total lack of idiomatic language in many subtitles. It's difficult, because even if what the actors are saying basically means something equivalent to an idiom in American English, the translator can't really use that idiom. It would sound really bizarre if Marcello Mastroianni said someone was a "dead ringer" or a "flash in the pan." But idiomatic language is an essential element of almost all communication in English and probably is everywhere in the dialogue of most foreign films. Just one of those layers of meaning that I'll probably never be able to unravel...