1) An inch is legally defined as 25.4mm exactly. A gallon is legally defined as 231 cubic inches. A pound is legally defined as 7000 troy grains, which are legally defined as exactly 0.06479891 grams. All Imperial measurements are derived from metric equivalents and have been since 1959. In other words, we've been on the metric system for more than 50 years. 2) Speaking as an engineer, anything involving math you do in metric and then convert anyway. 3) Speaking as a former elementary, middle, high and college student, everything you learn you learn in metric anyway. Bonus points if you spend any time converting. So really, whenever anyone says "we want metric!" what they mean is "we want new signs!" Okay, but every object in your life capable of displaying units - with the possible exception of your tape measure - already switches from English to Metric. Your phone. Your speedometer. Your thermometer. Your barometer (although I'll bet you don't have one). Wanna switch to metric? Buy a meter stick instead of a yard stick. Ta daa. You're done. Now all you have to do is show the courage of your convictions. Look up the temperature in celsius. Follow the little ring on your speedo rather than the big one. Buy some metric measuring cups (although god help you when you have to look up "Gas Mark four"). Yeah, you're stuck in the stone age at the gas pump, but trust me... ...you do not want to buy gasoline by the liter. Particularly in Victoria BC.
Ralisticallly, what they are saying is "we want base-10." Base 10 makes doing all of the little calculations we have to perform in our heads every single day far easier and much less annoying. It's pretty much objectively better, though how much so is quite subjective.So really, whenever anyone says "we want metric!" what they mean is "we want new signs!"
I think that's what they think they want. What calculations are those, though? Cook in metric and suddenly you're dividing by a thousand all the time. Dealing with distances? 100km or 62 miles, doesn't matter. How often do we think in yards? When we are, aren't we usually converting to feet or inches? In which case we're dividing by three, or that multiple of three, twelve. Really we want base 10 because we have ten fingers. Base 12 is much easier to work with when you're doing the math in your head because it's so much more divisible. Yeah, if you're doing big calcs Metric all the way... but weren't we just arguing on here a few days ago about how useless Algebra is to most people?