Yes, they should. So should Cuba. So should Iran. So should Russia. So should a lot of countries. But they are not (well, Russia's doing pretty well again) because the US has sanctioned the shit out of them. The US-dominated world financial markets have made sure doing business in those countries is nearly impossible and very often illegal.

If these countries are so badly governed that they will fail on their own there is no need for sanctions. We can't actually see the results of their alleged bad governance, because they have to spend enormous amounts of time and money just to do business with the rest of the world.