Having said all that, I'm not sure whether this is really on-topic. The original article is very interesting and an example of American measurement system that improved on an imperial precedent.
Ordinary gains are about 4% a year (long-term returns of broad investments in the stock market, adjusted for inflation). If you buy a piece of equipment for $100 it should return $4/year (on top of maintenance costs, depreciation, and the like) otherwise you'll do better by buying a stock-market index fund.
How much do you think it would cost an arbitrary manufacturing company to switch over all their tools and equipment to metric measures, update and test all their designs and schematics, run them through any applicable regulatory agencies, and such? Include the cognitive up-front cost of switching, maintaining dual toolchains and inventories for any gradual transition, the opportunity cost of the profitable projects you would have to postpone while your company experts see to the metric switchover, and everything else. Consider adjusting the return downward a little to account for appropriate risks in this process.
Do you see savings substantially in excess of 4% a year? If so, that's extraordinary, and a worthwhile investment! If not, the company would do better for itself and its shareholders by spending money elsewhere, or returning that money through dividends or stock buybacks so it can be put in a stock market index fund.
If nothing else, the $N billion of nationwide switching costs could have been used on, like, renewable power, or something.
Other things which are better that we'll probably never have include broader gauge railways, Dvorak for everyone, Wankel engines, and Betamax (vs VHS).
Nearly all of the world and most science and engineering measurements in the US have managed the conversion, so why not the rest of the United States?
If the change is performed, the time gained by absolutely everyone making use of more saner unit system could offset the cost? maybe just by avoiding errors?
This are ideas that has to be transformed in order to be shared with mostly everyone else.
Shameful confession, I do use pounds for weight.
The general idea in most of these arguments is that "more sane" is a very hard thing to define. There are cases for which metric is more useful. There are cases where it's less useful. Yet the argument is almost never actually made that way; metric tends to be presented as an ideally perfect system not susceptible to even the most trifling criticism, and any case presented in which it's disadvantageous compared to an alternative is dismissed with an ad hominem attack implying the person making the case is just too much of a stupid American to grasp the heavenly best-in-all-possible-cases-for-all-people perfection of metric.
Truth is it's an arbitrary system optimized for a particular set of use cases. The traditional-ish units used in the US are a different arbitrary system, optimized for a different particular set of use cases.
> Truth is it's an arbitrary system optimized for a particular set of use cases.
Which is a particular set of use cases.
Besides, what are we saying to a future Martian colony with conversion to an Earth-centric unit? The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole. Do we think our Martian brethren will be ill educated in history? Would Mars demand its own metre? Are we sending a message of Earth's lasting dominance over the colony?
Perhaps, if we convert, we do the simple change of 1 foot being defined as the distance light travels in one nano-second. Its pretty damn close to that already, and then we don't have issues with Mars.
/s