There are plenty of people with different (and terrible) haircuts, but that's part of what makes us unique. So it's not too surprising that Kim Jong Un is trying to squelch that creativity out of the North Korean people.
He not only wants all North Korean men to have the same haircut, but he wants them to have his haircut. They used to be able to pick from a list of state-approved hairstyles, but no more. They have one choice.
According to TIME.com:
Pyongyang introduced the new law two weeks ago but is now rolling it out across the country. Unfortunately, some North Koreans may not be thrilled about the new look. According to a former Pyongyang resident now living in China, the Kim Jong Un cut is unpopular because it apparently resembles the style of Chinese smugglers. “Until the mid-2000s, we called it the ‘Chinese smuggler haircut,” the source told the Korea Times.