What does the story of Amani and the Madras people reveal about the nature of human desire and devotion?

Chapter 29 uses the interactions with Amani and the Madras people to draw a parallel about human motivations. Amani's childlike longing for rupees is presented as a simple, transparent form of self-interest. The text then explicitly states, "The same longing exists in elders too - the running about is only for self-interest; only rare ones have the sentiment for the highest good." This observation is later exemplified by the Madras people. Hearing of Baba's generosity, they started a devotional program. However, it's noted that while their singing was beautiful externally, it was driven by an "irresistible greed for money" internally. This illustrates a teaching that much of what passes for devotion can be tainted by underlying self-interest, a trait common to both children and adults.