I think literal meaning here is misinterpreted as sincerity by OP. Which is a misconception, literal things can be untruthful and abstract things can be truthful as well, being abstract, or going in a roundabout way is not necessarily about being dishonest.
I think the OP is pointing out the lack of depth in the writing. Sincerity isn't about using language at or below 2nd grade, sincerity can be expressed with any level of verbosity. I think the trend of dialog being over-simplified to the point of literal noun-verb-noun with no metaphor just makes everything taste like plain white bread and velveeta. That's great: if your tastes are pedestrian, but there's nothing elitist or insincere about wanting greater depth from art. Ironically the screenwriters that utilize this richness of language are rarely blockbusters or award winners.