Rumors of Technocracy
I suspect that “authoritarian high modernism” is based, not on engineering rationality, but on rumors of what engineering rationality is about. In the real world, engineers are unlikely to throw away precedent. They think about things that can go wrong with plans.
The other side of the rumors of technocracy, is that “They“ cover up disasters (with a lack of evidence). I suppose it's not astonishing that the same corner of the political system that insists on compelling people not to waste they own money is also suspicious of high technology.