Simply put, they do not know things can be better, and they wouldn’t know how to make them better if they did.
This sounds like the White Man’s Burden. The people who live in DPRK are well-equipped to know what makes a happy and healthy life. They’re not any more brainwashed/blindly obedient to “the party” than people in the West are.
The only standard that applies is the happiness and health of the people. Saying that they “don’t know” or “wouldn’t know how” dehumanizes the people who live there.
There’s disgrace in describing people this way. Do better.