Except we aren't blameless either for the state North Korea ended up in. We leveled nearly every building in the country, we even targeted rural thatch huts with bombing runs. We dropped so many bombs on North Korea that the bombers started dropping bombs on thrice bombed rubble and open land because they couldn't find any targets left to attack. Why should we be surprised that a strong arm authoritarian leadership rose up among the chaos and put every effort towards military power and obtaining nuclear weapons at the expense of everything else?

I can't even say that they made the wrong decision either, North Korea still exists as an independent nation which is amazing in itself.