Nice to see you Oberon, I thought you were dead....
I tend to agree. You had the same issue with Iran. When the USA and Israel were looking into dealing with Iran's nuclear program militarily, they seem to have reached the same conclusion.
Most of Iran's research facility were spread out around the country, some in cities, some in deep underground facilities.
Even with a massive strike, there was no guarantee you could take out the entire program without using tactical Nukes and/or minimizing civilian casualties.
Even if the strike worked, the most likely result would only be to delay the program by 5-10 years.
I would think the same analysis applies to North Korea.