SAE is popular because 1 unit of things is convenient and weirdly coincidental to body measurements. One foot is approximately 1 FOOT. A finger is about 1 inch wide. Fahrenheit has smaller units and people can regularly detect 1 degree of change (imagine a measurement system where one unit of the main unit of temp was equivalent to 5C, and someone says just turn the AC up ONE notch). Can anyone common to metric tell me one part of their body which is 1Cm? (I'll wait...)
Trying to get a country to change their system of measurement is more difficult than you might think. France only adopted it during the French Revolution because, prior to this, they had no national system of measurement; each province had its own system. The Metric system brought stability to trade, with its standardized units. Other countries, such as Spain, Italy, Germany (Holy Roman Empire) were in the same boat: local systems but nothing on a nation-wide basis. Implementing the Metric system made sense to those countrie
In the US, on the other hand, we had already adopted a national system of measurements, and there has never been a good enough reason to up-end everything. Changing measurements would mean changing not just road signs to km and gas prices to $/liter, but would also mean changing packaging of food items, measuring utensils in kitchens, recipe books, and countless other day to day things.
Frankly, to most of us, it just isn't worth the hassle to make the switch.
In the US, on the other hand, we had already adopted a national system of measurements, and there has never been a good enough reason to up-end everything. Changing measurements would mean changing not just road signs to km and gas prices to $/liter, but would also mean changing packaging of food items, measuring utensils in kitchens, recipe books, and countless other day to day things.
Frankly, to most of us, it just isn't worth the hassle to make the switch.