Earlier quoted context omitted.
Because adding 7/16ths of an inch to 7/8ths of a mile and getting an answer in inches isn't easy for a human. Adding 1cm to 982m and getting an answer in centimeters is dead easy for a human. THAT'S why human intuition about measurement doesn't mean a damn thing. Using metric means using the system optimized for humans. Period.
Your absolutism is a bit silly. I don't think the Imperial system is good for anything beyond construction or cooking, but there's a reason it excels those areas. And it's exactly because it's more usable by humans in certain contexts (like construction or cooking). 1/3 of a meter should not be an irrational number - how is that "optimized for humans"? A scalable system that shares the divisibility of the foot would…
Measuring dry goods by volume instead of by weight? Good luck ever getting consistent results.
Base 10 math is the most intuitive for humans. Fractions are an abomination.