> But "the" metric system, so called, functions entirely on the happy coincidence of macroscopic distance being divisible at human discretion
What do you mean exactly? Any distance is divisible arbitrarily, it’s a continuous scale regardless of the unit system. We could define the metre as a foot (or rather, as the distance of some physical phenomenon close enough to a foot) and build a decimal system out of it, and it would have the same advantages as the metric system.
> while the similar and simultaneous effort at decimalizing time foundered on the rocks of how long it actually takes Earth to revolve upon its axis and to circle the sun
The fact that there are 60 seconds in an hour and 24 hours per day has absolutely nothing to do with how quickly the earth revolves. Your argument works (kinda) for the number of days in a year, that’s all.
> Both efforts originate in the same silly hamartiac human desire to prescribe a shape to which reality must conform
No, this is completely backwards. This effort originates from the idea that we should observe and understand nature, and build a rational society based on this understanding. The original metre was a fraction of the length of a meridian for a reason. They did not change the size of the Earth to conform to an arbitrary unit. Instead they came up with a unit that made sense to them, for both philosophical and practical reasons. They did the opposite of what you say.
> Especially since, in another example of its designers' foolishly misplaced priorities, metric offers no units at the human scale
The metre is about 2 thirds of an average human height (give or take, the average also changed with time). How is that not a human scale? If you want to go lower, to the scale of something you can hold, you have centimetres. If you want to go larger, to the scale of a distance you can walk, you have kilometres. And all conversions and comparisons spanning the 5 orders of magnitude relevant to our daily lives are seamless and make sense. What is your problem with this system?
> They may have prefigured the brutalists in this way
That is actually hilarious. The enlightenment philosophers and humanists who came up with the metric system are polar opposites of the brutalists. They rationalised our understanding of the world around us. They did not rebuild it square.