I am curious as to what we'll do with all that surplus computing power after crypto currencies (or mining on general purpose hardware) fade out of fashion. Better weather forecasting? AI? And don't forget the investment on cheap power sources.
How do you think this people with their cards are going to do anything else with it? There does not exist a single computing power but 1.000.000 single ones and the only reason they waste electricity is because they get money for it.