Survival of the fittest. That's why the system works so well. It's actually designed in an evolutionary way to ensure continual development and destruction of the old if they cannot keep up with the times. It's really clever if you think for a moment. A self-cleaning mechanism for when corruption or laziness or greed set in. It cuts all of the non-performers out at the bottom by making the mining process too costly for them, and then opens up a path for whoever wants to join in, providing they can do it better than those did before. Better keep yourself afloat or get out.