Refusal to open up to China, to develop, to stop giving Japan and SK a reason to hate China and keep their American bases everytime they threaten to invade or nuke them.
So why isn't China's closet ally included in the belt and road?
The alternate reason is that China actively keep NK in it's pathetic undeveloped state, which is horrible, and again, unproductive.
Refusal to open up to China = no influence? ....LOL. Japan and SK hate China even without NK, and China ultimately gives no fcukks about what US poodles in Tokyo and Seoul think.
Look at NK on the map, their value in B&R is small even if they invited themselves.
NK's development level is Kim's call, not Xi's. They serve China's purpose just by being there; while not as blingy as South Korea, NK isn't the pathetic unproductive state the western media likes to paint. They don't have a homeless problem like in South Korea, while possessing hypersonic weapons which the US don't.