[Byron]

There are some things so embedded in a national psyche as to what is appropriate that no amount of persuasion by any fashion "trend setters" will make the slightest difference.
You surprise me at turn-ups on jeans legs still being advertised however as that fashion was finished with when I was a kid. We used nevertheless to select our jeans with or without boot-cut , even if we had never been near a horse.

I would love to do a survey on US rodeo riders and find just one who might be prepared to wear pencil jeans and have them "wrinkly" at the leg bottoms.
MOST unlikely as this iconic apparel will belong always with the concept of hard work on the land and being in the saddle all day, herding cattle - it goes back to the ideals of the early days of the tough frontiersmen forging their way westwards from the eastern cities.

As to boots worn in the USA I have a question. They will often be to calf-height and with the most elaborate tooling on the leather - quite some works of art but never seen because the jeans are worn OVER and not INSIDE them - so why such decorative work on something always hidden?
It used to make me laugh to see George Dubbya walking across a manicured lawn as if out on the rough and dusty plains of Texas (with T. Blair in tow trying to look the part as well with thumbs in pockets)