It depends on one's definition of dictatorship. I personally do not believe, for instance, the British Crown is one such instance.
The British Crown had to concede some rights centuries ago, or there would have been civil wars and probably no more crown. Dear Leaders are the ones that don't have to concede anything, yet.
Besides that, multiple ways to read this. "Monarchies" could've been a reference to pre modern monarchies of which many made it through at least 3 successions. Or as a correction to the upper comment, saying that the Kim's are more monarchy than plain dictatorship.