Too subtle for its own commercial good?

Or, in Hamlet's words, caviar to the general. As this board shows, the film is pitched above the heads of too many viewers. Can I suggest some clues towards appreciating it better?
1. It is a prequel to Chaplin's 1967 film ''A Countess From Hong Kong'', in which an inhibited American diplomat falls in love with a penniless dance hall girl who is a Russian countess.
2. It is a partial dramatisation of Ishiguro's surrealistic 2000 novel ''When We Were Orphans'', in which a lonely driven Westerner in Shanghai in 1937 pursues his personal quest, quite blind to the upheavals around him.
3. It uses Ishiguro's deceptively flat prose (by Pinter out of Beckett?), in which words hide true feelings or erect a screen of false emotion.