Survival of the fittest. When a society values the productivity of the individual and allows the individual to keep the fruits of labor, the society is strong and vibrant. When society compels producers to give a significant portion of the producer’s bounty to the non-producers, non-producers multiply, producer output declines, and the society dies.
But that doesn't stop the Bernie Sanders types from sitting around the campfire pushing their message (while BTW the real producers are out hunting for big game).