The lore I've heard is that hire-for-life system was supposed to create psychological safety as a response to excessive siloing habits exhibited by WWII veterans, after surviving in reverse order of their individual bus factors - e.g. skilled maintenance crews, medics, were more likely to be spared in last-ditch assaults, which happened a lot in the war.

IMO, that after series of economic downturns and corporate restructurings during 80s-00s in turn created excessively risk-averse Japanese corporate culture; now that they can be fired, psychological safety was gone, and now maintaining hire-for-life eligibility was seen as crucial. It may have been implicitly reinterpreted as eliminating others is a must for survival.

That's clearly one of major contributing factors to counter-productive behaviors causing stagnation of traditional Japanese tech companies; outright refusing sales, exports, opportunities, that may affect internal politics and justify job terminations.

It sucks to watch a lot of cutting edge technologies slowly evaporating from such fear of terminations. Hopefully someone figures a way out.