Dictatorships that control their subjects' access to information like to have all Internet connections in their country pass through a single choke point so that they can maintain control. I once visited Saudi Arabia and met the guy responsible for all Internet traffic in and out of the country -- through a single link with a single backup.
This is good if you want to give your people only the access you want them to have, and to block everything else. At the same time, it means your whole country can be knocked offline by a single attack, which seems to be the problem N. Korea is experiencing. Imagine trying to knock the entire U.S. offline! It couldn't be done.
Cuba, OTOH.... well, that one may change soon. But N. Korea? Probably not, although I wish it would. A far more miserable place than Cuba has ever been.