Well, it cost your US economy yearly billions of dollars to keep your old archaic imperial system alive.
Next to that don't forget that hundred of millions of dollars were spend on special correction lenses for the Hubble, just because the US uses the old and the new system simulaneously.
Is it all worth that, other than for shortsighted personal hard headedness? Take an example to the country where your imperial system originated : here in the UK most old imperial values have been replaced, with as main exception the Mile and driving in the lefthand lane.
You already drive in the righthand lane. Now only the rest has to follow ....
Yes I knew that was a joke. On the position of gear shifts : it would be worse if they placed them on the 'correct' side, but still demanded to keep driving on the left hand side of the road ! Specially if they kept the stearing wheel also at the lefthand side !
Sarnian - actually the term "fortnight" is distinctly a British one, so don't blame us Yanks for that! And as for the "wisdom" of how the Brits measure things - let's see, road signs are in miles and yards, petrol is sold in litres while beer is sold in pints, a person's weight is measured in stones, and you don't know what a proper gallon is -- go figure!
Ok : I'm off to the pub 6 Ramsden's chains, a link, and a perch away to have my daily pint for 2 Pounds 20 pence. I walk to keep my weight stable at 12 stone, 3 pound, and 2 ounces with my lenght of 5 foot, 2 palm, and 2 inches.