I have always thought that this parable should be called the parable of the forgiving father.
This poor Father is saddled with two miserable sons.
The transgressions of the younger is obvious. The transgressions of the older are far more insidious. Upon hearing about his brothers return the older brother refuses to talk to him. Yet he seems to feel he knows how the money was spent. Never in the story do you hear that the younger son took up with prostitutes except from the older brothers mouth. I've known many people who have easily blown a fortune on just drinking without giving any thought to where the money was going. Let's not forget how many friends a man has when he has money. The older brother has obviously spent a fair amount of time thinking about what he would have done if he had taken his inheritance. In this whole story all he cares about is himself. He is serving father only for what he can get in the end. In essence he says "I've been good and I deserve something for it!"
So the younger son in essense says to his father "Your gonna die someday - Give me what I will get when you die!" The older son says "I follow your orders not because I love you or because it is the right thing to do but because I expect a special reward!" Each son is focused on himself and his own wants.
The father loves these two jerks because he loves them. Even when they are the most vile he still loves and accepts them. To the father it is not about the things (He does not promise to give anything to the younger son except love and acceptance)... It's not about the stuff to him. The father had to go out of his way to bring each of the sons back into the family. The father overlooks each of his sons selfishness and tries to bring them home.
It's all about how God tries to bring us home even though we would rather hold on to our own selfish desires.