And yet in Australia:
- Most baby boomers will still use "inches", "feet", "yards" and "pounds"... be damned if you even try to correct them. (Remember: a cricket pitch is 1 chain or 22 yards in length)
- Nearly everyone in Australia still quotes their height measurements in colloquial talk in feet and inches.
- Baby birth weight announcements are still very common in pounds and ounces.
- Qantas and Virgin base the points you earn and burn on flight miles, not kilometres.
Of course, they are limited examples, so let's not get carried away.
US has tried to aim for metrication before, though sometimes the only thing more difficult than metrication is gun control and the 2nd Amendment. In other words, met stiff resistance.
Some industrial / professional arenas may never move past Imperial (or at least have key parts of them in Imperial), for example, aviation.
Just to pile on the "while we are at it - US edition", why not 24 hour time in commercial aviation? Are most Americans that dumb that they can't learn 24 hour (or military) time?