When I went through that process nearly 30 years ago, I wanted to learn on Dad's car with the 5-speed. I felt since manuals were cheaper, the driving school would surely have manuals in their cars, and I wanted to know how to shift one.
If it hadn't been for that, I probably never would have learned to drive a straight. The driver's ed cars were automatics, my mother's car was an automatic, my first three used cars were all automatics. When I bought a 2012 Ford Focus, I was going to get the manual transmission, but I would have had to special order one, and the self-shifter supposedly delivered better fuel economy anyway. (It did work quite well.) When I traded the Focus for an F150 in 2014, it wasn't possible to buy an F150 with a manual transmission in any special order configuration. Take the automatic, or buy a different brand.
I've driven manuals in a few random, borrowed vehicles, but I've never owned one, in spite of quite liking to change gears, and always wanting a vehicle with a manual transmission. With all of this being the case, I just can't see the point in requiring American drivers to learn how to shift a manual transmission. Most of us will never encounter one, even if we're looking.
These days, big trucks don't have manuals anymore either. I'm good at shifting gears, because I've logged almost 2,000,000 miles behind the wheel of tractor-trailers. I once had the pleasure of driving 600 miles with no clutch. I haven't had a shift lever in four years though, and I haven't had a clutch pedal in three. Even class 8 trucks have automatics these days, unless you go way out of your way to specify otherwise.
Shifting gears is right up there with those handy dandy hand signals, and knowing how to crank your engine over without breaking your arm.