The fact that a mile, gallon, pint etc. all have different meanings, in different countries, just highlights the fact that there needs to be a standard, hence metrication.
Why do you say this? What possible difference can it make to me what units are used in South Africa (or anywhere else)? I buy 10 gallons of gasoline, I know how far that fills my tank and I simply don't care if liters are the unit of measure elsewhere. [snip]
The thing is, other people sometimes need to decipher US units.
Trying to decipher US cook books is horrible. Cups of this, sticks of butter, pints (that are a different size) of that... At least in UK cook books they tend to have dual units, Imperial and metric — this is one of the odd arbitrary places that Imperial units are still commonplace here — but US cook books almost never have anything other than US customary units and make the parochial assumption that everybody will understand them, even in books intended for distribution in non-US markets.
I wouldn't be too surprised to find that a part of the US's trade deficit is down to using archaic units that are at variance with the rest of the world. There's, for instance, a huge international market for M6 bolts,
1/
4" not so much.
I'm of just the right age to have had formal education in both Imperial and metric units. Junior school was all in pounds, shillings, feet, miles, chains, acres, pints, gallons and senior school was all metric. At the time many folks, like yourself, were quite reactionary about metrication but most people just got on with it. We took a pragmatic approach to metrication, in everyday life we still use pints and miles, and many pack sizes of things although formally specified in metric are still the same as they ever were. One gets supplied 568ml of beer and 227g of coffee, but you ask for a pint and grab a
1/
2lb bag from the supermarket shelf. As time goes on the older units get used for less and less and old units gradually fall by the wayside (for instance, petrol was dual priced in both gallons [proper ones, not the US mini-gallon
] and litres for perhaps 25 years, for the last 20 years or so we've only used litres).