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.
It's quite simple: mass market content is made for the lowest common denominator. See also, Jack of all trades, master of none.
It's not a phenomena unique to movies, or the modern international economy, it's a pattern that pops up all over the place. Look at multi-tool pocket knives: capable of doing many things, but mediocre at everything.
