Let me see. They have major concentration camps, for their own people. They hate our guts, in an unbelievable way. They threaten us with nuclear weapins, and they also would attempt to destroy is if they had the means to. I'd say YES they are cynical and evil, don't believe me then check this out. ( https://www.youtube.com/watch?v=Lr6Rw0ltFxc ).
A nuclear armed Korea is definitely considered unacceptable because of several different questions.First of all they tend to not cooperate with weapons inspectors and the country is run by a dictator that may change their mind on a daily basis which makes it hard to predict for the rest of the world.
Yes, North Korea's government is too irrational for them to be permitted nuclear weapons. As the recent purge of Kim Jong Un's uncle shows, North Korea is still caught in the paranoia of the most ruthless forms of totalitarianism. This is not a government that needs a nuclear arsenal at its disposal.
Sure, NK's nuclear weapons are a threat to the world but guess what? America also has more than 2000 active nuclear heads. It does not make sense how NK is a threat when the US has it as well. Realize that US is also the worst country of all as it is the main reason for the global violence around the world.