SI units ARE arbitrary in the context of humans. A foot is derived from a physical size of human feet. So the size of the units is human-scaled in ways that S

SI units ARE arbitrary in the context of humans. A foot is derived from a physical size of human feet. So the size of the units is human-scaled in ways that SI never are. That said, in engineering school we never used imperial, only SI. And it was far easier. But that's not the general public. Related to this: Fahrenheit: Human-scaled temperature Celsius: Water-scaled temperature Kelvin: Atom-scaled temperature