I am of the opinion that Jesus was countering the society in which He lived by showing that the Kingdom of God opposes it. In other words, this story is quite revolutionary. I would suggest that even today this is a revolutionary concept depicted in the parable of the wedding feast. It seems to me that this reveals the radical nature of the Kingdom of God as being one of inclusion not exclusion. Our various churches tend to be, with few exceptions, exclusive.
Society is the same.
A sermon might go into history a bit and show the times when the Catholics, the Irish, the American Indians, the Germans, the Blacks, the Asians were all discriminated against and yet here in the parable the Kingdom of God is depicted as inclusive. This is, in my opinion, what the church should be if it takes Christ seriously, if Jesus is Lord not just by saying so but by doing so. Imagine going out into the streets of New Braunfels and inviting just anybody to you special wedding feast of celebration. You d want your servants to select the guests with the guideline being our kind of people. But not so the Kingdom of God.