What is the aim of Desai's story "A Devoted Son"?

The wording of this question leaves possible answers fairly wide open. The question could be asking about a moral message, thematic message, or some other kind of message; therefore, answers will vary from reader to reader.
I think most readers could make a case that Desai's story is a story that teaches readers the importance of family and doing what is right by that family no matter what. Rakesh's actions frequently make his parents both incredibly proud and incredibly disappointed. For example, his father doesn't believe that Rakesh should have come back home to practice medicine, nor does Varma believe that Rakesh should have married a local girl. Rakesh does both of those things because he is proud of his upbringing, his home, and his family. He wants his own kids to have a similar experience.
As Varma ages, he becomes angry and bitter at the help that Rakesh is trying to lend. The story ends with Varma asking to be left alone to die, and that's not necessarily a reaffirming message; however, I think it is important to note that Rakesh simply refused to give up on trying to help and care for his father no matter what. He did what was right and not what may have been easy.