The economic implications of the third story are a twist on the first two. From a human point of view, it is easy to see how the scribes and the money-loving Pharisees can easily identify with the resentment of the elder brother. Sunday's epistle suggests that the foolishness of God is wiser than the wisdom of mankind. That may be, but we are, after all, human. Like it or not, we can all identify with the elder brother.
Many people leave their entire estates to churches or other charitable organizations.
Human nature being what it is, I'm sure that some of their children resent that. The final parable ends with no indication of what the bitter brother is going to do. That's the point. Lost sinners are being found. If there isn't one on earth, there will still be one in heaven.