I really don't see why the metric system is so inherently superior in non-scientific use.
It's just simpler and more intuitive.
Do you know off the top of your head how many feet make up half a mile, and how many meters make up half a kilometer? Which one is simpler to do in your head when needed?
Do you know how many teaspoons make a tablespoon, make up a fluid ounce, make up a cup, make up a pint, make up a quart, make up a gallon? Isn't that a bit... needlessly complicated? Hell, I can never remember how many ounces are in a cup and that's screwed up my cooking on several occasions. Wouldn't it just be SO much simpler to have small volumes measured in milliliters, and big ones in liters? And for intermediate measurements, just round to the nearest 50 or 100 mL? Certainly beats keeping track of the incredibly complicated system used in the US (never mind the fact that some of those terms are used identically in other places, but for different volumes).
Those are just a couple of examples, but using the metric system really does make life a bit easier.
Actually, the size of a meter is no longer related to the Earth's circumference; it is officially defined as the "length of the path traveled by light in a vacuum during a time interval of 1/299,792,458 of a second
