In a number of instances where there is not a standard in place already it is not uncommon to see metric measurements mixed with imperial or US customary measurements.
I’m not in any way shape or form claiming that ALL of it is mixed.
However what does actually happen is the a unit of measure might be mixed with a customary one and then that becomes the defacto measurement, you may see wire resistance shown as a mix of Ohms/1000ft.
I am not getting into an argument about the merits of metric, I’m on board, I am with you. That doesn’t mean there aren’t some silly oddballs.