Don't be ridiculous. It would be just as silly to have velocities in both m/s and km/h in a same paragraph. And many, many more people in the world know the con

Don't be ridiculous. It would be just as silly to have velocities in both m/s and km/h in a same paragraph. And many, many more people in the world know the conversion factor between those than between mph and fps. It's pretty bold of you to talk about 4% of the world's population as "the rest of us", but unfortunately it's to be expected from a certain type of American.