There was a Star Trek: The Next Generation episode that sorta dealt with this: Captain Picard was stranded on a planet with an alien. While the universal translator was capable of translating the individual words, the meaning was completely cryptic because they spoke in metaphors. An analogy was made that if we were to do that in English, we might refer to a romantic setting as "Juliet on her balcony."
Off-topic question:
What I never understood (and part of why I think
Star Trek is bad science-fiction) is how that society is supposed to work.
I mean, if the language is
purely metaphor, and "Juliet on her balcony" is the
only way to refer to a romantic situation, then how do children assimilate the language? If you have no way to tell a child who Juliet was, or explain the plot of "Romeo and Juliet", then how are they supposed to know what "Juliet on her balcony" is supposed to mean? Within a generation your language becomes a set of metaphors that nobody understands. If there's no concrete basis to the language - no way to say "this is called an 'apple'" - then there's no way for a neophyte to assimilate the language.
And if they
do have a way to explain their vast scope of metaphor to children, why didn't the alien talk that way to Picard?
I know, I know. It's just a TV show. But it's a stupid one.
(Your point is, of course, valid.)