"The schism between the royal family and the Sheikah must have something to do with it. I was already thinking, before, it might be that the conflict broke out when everyone first realized what was happening, and you'd get the usual pointing fingers and banishing blamable parties... but if the Sheikah engineers knew all along, they might have been hiding it from the royals. There's so much to unpick there, since—Symin is better at this than me—there's an easy allegation, maybe even true, that the Sheikah were trying to weaken the royals' power, by crippling the hereditary light magic that's their claim to divine ordinance—
"In which case the project must have been cut short, aborted in an incorrect way, to leave them buried and inactivated but still passively draining power. If the King executed all the engineering leadership there might not be anyone left who understood the system enough... I think not many people were fully in the know, because some of the notes we read the writers were clearly in the dark..."