Even the actual engine-eer of the old steamship or locomotive didn't care anything for a measuring system.
The engine-eer was the guy(s) shoveling coal into the furnace under the boiler. They would have to watch a pressure gauge. They weren't reading off PSI or kilopascals or bars or inches of mercury. They were watching a dial with a red line on it and putting that needle where the conductor/captain has requested in terms of a fraction or percentage. Full steam? All the way to the red line. Half steam? Halfway.
In our modern cars, we press a gas pedal to regulate the engine torque. The actual engineers have given the pedals the response they have. The length of throw, the linearity of the response, etc. And this basically gets tuned by test driving and tweaking. Plus, there can be some differences in how the controls respond due to nothing more than personal preference. Like how BMW puts 70% of braking force in the first 4mm of pedal travel. The driver is experiencing the results of the engineering, not the measuring system used to do it. The temp gauge, ditto. Do you know what temp your engine runs at in C or F? I only care that the needle in the middle of the temp gauge and the light is off. I've never had a car that displays gallons or liters of gas. There's just a needle and a mark every quarter.
Responses like "we'll never metricate our road signs because we don't care" serve the US no purpose and make the country look like a land of morons.
Apologies to other Americans. My personal view is that most Americas
don't care about metricating, ever. In fact the majority would be against change. The same way that Swedes didn't want to switch to driving on the right. Like bsfeechannel has said, this is one of those things that wouldn't happen unless the government circumvented the popular vote. But in this case, we really don't have a befit from doing this other than politics and money changing hands. So I think the majority of Americans are perfectly justified.
This isn't to say that some university (idealistic, book-learned) led movement might not ever get a voting majority. In today's internet age, you never know what movement will get temporarily united people with nothing better to do than to experience the rush of exerting their collective power to do moronic things. (Which this is a staple thing to do in any change of power; change for the sake of change).
I would guess that even the majority of Americans who have immigrated as an adult from a pure metric country would be against change after 3 months of living here. It just doesn't matter, once you have gotten used to it. In our grocery stores, the price of everything is marked in on the shelf in dollars/oz for comparing prices between products sold in different sized containers, even.
Do you think the electronics component industry would benefit by changing all 2.54mm spaced components and breadboards to 2.50mm spacing? Or would this just cause us all extra work and expense?
Most of our engineers use metric. Our architects and civil engineers use a lot of imperial, still. And they are totally fine with manipulating the physical world in metric and/or imperial. Most EE have to deal with tons of arbitrary choices and decisions. They have a million ways to achieve the end results. Dealing with optimizing input and output ranges at every stage. Metric and imperial is nothing. Not but a drop in an ocean. Not but a state of mind.
If you think this "makes the country look like a land of morons," that would be your opinion, bsfeechannel. W/e country you hail from thanks you for not wearing its flag.
This "land of morons" maintains its economy and standard of living by maintaining a technology gap/advantage. This is why we spend so much on military and for subsidizing our airplane and other tech industries. 60 years ago it was the auto industry, but the world has caught up, there.
One of the things I personally like about imperial: if you can engineer in imperial, you can (and you probably have to) engineer in any other system, including metric. If you can engineer in metric, you could be a productive-enough cog in a larger machine via monkey-see monkey-do... but you might still be a moron who confuses the real world for numbers. The relationships are real. The formula which describe those relationships are real. The numbers of the units are a figment of your imagination.
Take the ATC example. You could say that km/hr is better than knots, because altitude is in meters. But "per hour" is completely arbitrary, too. Yes, there is a relationship between speed and distance, but the ratios are arbitrary. In engineering, you are constantly adjusting a knob so the signal of interest fits on the screen. The numbers never go exactly to 10 until an engineer determines what the range is and puts the knob on there that goes to 10.