In the sentence that you quoted from Kim In-sik I think the key word is 'fundamentally' - he is not saying that the two societies are the same but that the mode of production is the same - capitalism. In other words it is divided into a class that owns the means of production (bureaucracy) and one that does not (workers) and its economy is driven by the logic of competition and capital accumulation. Just because a country is poor, totalitarian and militaristic does not mean it cannot be capitalist. Of course I'm sure that Kim In-sik wouldn't deny that South and North Korean societies are different in many other ways, but his point is a polemical one against he NL people who say that North Korea is a socialist society.
By the way Kim In-sik did not win the position of chief policy-maker, but got about 17 percent of the vote.
"..fundamentally exactly.."(*), according to your contribution(last january).. But later(perhaps tomorrow) more about it!!
* "I believe that North Korea is fundamentally exactly the same sort of exploitative and repressive society as South Korea."