I don't think it's just the "rules" for a Chinese audience (though that doesn't help); I think it's the economics of making movies primarily for a global audience, rather than a particular language, culture, or even sub-culture. This was an "aha" moment in realizing why so many movies over the last decade contain seemingly lazy, blunt dialogue, lacking subtlety or subtext: the meaning needs to come across clearly in subtitles and dubs, divorced from English idioms, cultural context, and intonation.