I must be an American thing. It's such an easy thing to program. My kitchen scales can even be set for pounds and ounces, although the resolution drops from 0.05oz to 0.1oz on the pounds setting, because the display doesn't have room for the extra decimal place.
I don't think it's entirely about programming. It would be so confusing. Suppose your receipt said this: "0 lb 8.5 oz at $8.99/lb thus $4.76"
Can you imagine the confusion? How could you ever check whether you had been charged the correct amount without a calculator?
The reality is that America is decimal, and has been for quite some time.
In engineering, weights are in pounds (lb), thousands of pounds (Mlb), or millions of pounds (MMlb).
Distances are in feet, hundreds of feet, or thousands of feet. Road signs will say "500 ft" when giving a distance to a hazard.
Also in engineering, measurements are in inches and thousandths of an inch (mils). The dimension of a part will be given as 2.351 inches. Pins on ICs or headers are 0.1 inches apart.
It makes sense. Decimal is the only sensible way to make measurements and do calculations.