Outstanding! Yet the largest economy in the world isn't metric. I wonder if causality applies...
The other economies are not so large because they spent all their money converting to the metric system.
Jokes aside, let's dismiss some myths.
People have to have in mind that the first country to abandon their customary units in favor of something less insane were the French themselves. Other countries thought it to be a good idea and voluntarily adhered. So, the French didn't impose their customary system over the other countries.
People who like to raise the "perils" of converting to metric often cite the
Revolta do Quebra-Quilos (something like the "break-the-kilos" revolt in English) in 1872 in Brazil. First, it happened in a specific region of the country, and the reason for the revolt was that in some towns the old standards were suddenly banned and people were forced to immediately buy or rent new certified metric scales, weights and containers. This, together with other problems, sparked the revolt.
So the rage was not against the metric system, but against the way it was done.
The other myth is that the metric system is "eurocentric". Countries that have adopted the metric system outside Europe don't have that
sentiment. Metric is
international. You can buy something from a distant country, and if a screw breaks, you can find it locally. You don't have to import it from a distant land just because of their whimsical standard. People don't even think of France when they use the system. It is so ingrained in the everyday life that I guess that most don't have the slightest clue that the French started it two centuries ago. I hope that I don't hurt any French pride here, but the truth is that the French are irrelevant for the system now, since the whole world took it over.
In short, no one gets less American for going metric.