Ha, North Korea is just a special place, isn't it?
It's actually not hard for most foreigners to visit North Korea. They're seldom refused visas (why turn down profit from tourism?). They just can't travel and tour on their own. Instead they have to go through a tour group that dictates their entire itinerary. However, they do tend to limit the number of American, South Korean, and some Japanese visitors. A lot of times they can go only in limited numbers and only during certain times of the year.
Too bad most people are only allowed to visit the capital city, Pyongyong, which was practically designed to be a facade. It doesn't at all represent what real North Korea is like.