Explain what you think these final lines mean: "And the association of owners knew that some day the praying would stop. And there's the end"

I think that Steinbeck is alluding to the fact that there will come a point when itinerant workers will reach a breaking point. They will cease to pray and will act with force. They will reach past their limits of endurance and take matters forcefully through their mass of impoverished and indentured numbers. Eventually the corporate hoarders of land and its fruits will be forced to capitulate.