Hello Chickey C.,
Both totalitarian societies had dictators that cannot handle their authority being questioned or challenged. Stalin and his reign became so radicalized that even the officers that were close to Stalin, turned on them during the Purges in the 1930s. He had them and their families either killed or forced to work in labor camps called gulags to be worked to death. These were innocent people that really believed in Stalin and his cause for the revolution. I am not sure what resources you have read from or seen but the film Burnt by the Sun really exemplifies how those that were Stalin's highest-ranking trusted officers were some of the first to be 'purged'. It is a good film made by Russians in the 1990s because obviously, they could not talk about these issues during the 1930s. It was incredibly terrible because these innocent people would be tortured into admitting to treason and then executed and their families as well. The Purges of the 1930s or the Great Terror have estimated the deaths of around about 20 million people. Kim Jong-un is no different than Stalin in that he is a dictator. He wants power and will do whatever he can to secure that power. He starves his people and is willing to kill even those that are closest to him if it means securing his position. And people do not have a say in the matter of what he does.
I hope I answered your question thoroughly enough.