Just last year, a Martian probe was destroyed because some of its navigational data was in feet, and some was in meters. All exported goods have to be labels in metrics or they do not sell. We are slowly getting our act together. Almost all packaged goods have both the standard and metric measures on their label. In truth, the US is using the metric system extensively, just not totally.
Doctors do all measures in metrics especially distributing medicine in cubic centimeters.
Virtually all scientists in the US use metric measures exclusively. Track and field events have dropped yards and miles all together. All new car speedometers are in both KPH and MPH, and many recent cars have KPH as the dominant measure. Ironically, speed limit signs are almost exclusively MPH, even on highways where distances are measured in kilometers. Here in Arizona, Highway 19 from Tucson to Nogales is marked in Kilometers.