Last 'slavishly devoted account' I can recall was Wilfred Burchett's _Again Korea_ from late 1960s, a reliable report in its day...
Post-war strength of 'self-reliance' ideology among North Koreans resulted from trauma of US bombing (as would be case later in Vietnam, more bombs were dropped on NK than on all of Europe during WW2) that destroyed almost all above-ground structures and either killed or wounded about 75% of population. Pretty strong basis for acceptance of 'juche.'
NK economic 'disaster' manifested itself in 1990s following decade of 'flexible & practical self-reliance' (as policy has been called) which meant attempts to increase foreign trade, direct foreign investment, joint ventures, tourism, & cooperation with South Korea. Hmmm... Michael Hoover