The NORK situation is quite different from Libya. Libya had several very different tribal groups, only one of which was really favored by Khaddafi. When it looked like he would do serious damage to the people in Benghazi, it was not hard to make the excuse to start a serious rebellion and enlist the enemies he had made over the years with executions, etc. Leader Kim may not treat his people well, but they are all pretty much Koreans, and very well isolated and brainwashed, so the situation is very different.
We aren’t asking there be a regime change in N Korea which was exactly what was sought in Libya. Kim will remain in office.