In the late 1700s, Thomas Jefferson wanted the United States to adopt a unified system of measurement and saw the metric system as the best solution. However, a pirate attack in the Caribbean disrupted these plans. Joseph Dombey, a French scientist carrying a kilogram and meter stick to demonstrate the metric system, was captured by pirates. By the time France sent another scientist to explain the system to the Americans, Jefferson was no longer in office, and plans to go metric were disregarded.
actually, they didn't need examples (even if it would make things easier.)
for example, the meter was originally defined as one ten millionth of the distance between the equator and the north pole. (which, given the necessary instrumentation, was something "anyone" could measure. well, instrumentation and instruction.) it's now based on the emissions of krypton-86, and the wave length of a certain part of it. Again anyone with the proper tools is able to measure this.)
Similarly, the kilogram was defined- originally- as the mass of one liter of water. the liter was defined as the volume of a cube with a length of ten centimeters.. (today it gets quite a bit more complicated, but based on observable constants...)
One of the ongoing goals in science is to reference all metric units to fundamental forces. Basically, we want a system where you can write down everything you need to recreate all our measurement systems.
Right now, most are referenced that way, but not all. Last I heard the kg was being difficult. I believe the plan is to reference it to a perfect sphere of perfectly crystalline silicon-28 of a given size. Creating such a sphere is extremely difficult however.
Powers of 10 is actually the main problem with the metric system. It makes geometry ugly as sin, and isn't sufficiently granular for convenient use in the kitchen.
Whatever asshole invented us with 10 fingers instead of 12 is begging for my boot in his ass. Geometry is elegant in duodecimal. But because we developed basic arithmetic with 10 fingers, we have to resort to ugly hacks like a sexagesimal unit circle to make geometry compatible with decimal.
And it sounds like Jefferson was already familiar with it anyway, if he was thinking it was the best system. I find it very doubtful that the only holdup was that there was no one to demonstrate it.