I don't know why they bother. No one in North Korea sees documentaries such as this - it would give the game away that other nations are richer than North Korea (which insists that it is the richest nation in the world, and that the US is the poorest). They ostensibly make this stuff for people in the West or in the South, but no one living outside North Korea believes it (aside from some very, very gullible communist-wannabes).
They're wasting what very little money they have, fighting a propaganda war that ended in the 1980s with the fall of the Berlin Wall. Oh and Funny Fact: no one is allowed to talk about the fall of the Berlin Wall. Even mentioning it in North Korea, or even being in Eastern Europe at the time as some unfortunate North Korean exchange students were, is enough to be labelled a dangerous traitor for daring to have witnessed a communist government being overthrown by the people. There are North Koreans who were in East Germany when the Wall fell - those silly enough to return home got imprisoned immediately lest they tell their friends and family of what happened.
Is most Pop-Culture trash? YES. Absolutely. But so what? Most culture, throughout ALL periods was trash. We look at the fine art of the ancient Greeks and Romans, of the Victorians and Renaissance painters, and we wonder why our culture is so inferior when compared to those past glories. Little do we realize that we are only seeing the VERY BEST of those older cultures. The muck and the garbage didn't survive the test of time - only the brilliant works did. This gives us a skewed view of past cultures. 1800s Europe wasn't brimming with Van Goghs. He was a rarity, an unappreciated rarity, in his own time.
Mark my words, 200 years from now, future generations will look back at our Great Artists and wonder how far their culture has fallen, and trash like "America's Next Top Model" and "Fiddy Cent" will have disappeared into obscurity.
But back on topic - North Korea, you've surely got more important things to spend your time and money on, like, I don't know, modernizing your agricultural system so your people don't starve and starve and starve.