i think it's more economics and the suburban lifestyle. in the USA the typical upper middle class lives on larger property, has a larger home, and works more hours, and retires later than many parts of the world. which drives lots of different things, one being more likely to have a home theater when that was in vogue, a larger 2 channel room when that was in vogue, and American hifi dealers sold different gear fitting different life styles.
they are not predisposed for larger speakers and big loud systems. but that is what was offered more so than other parts of the world.
other parts of the world have higher living densities, smaller homes/apartments, higher taxes, work fewer hours, retire sooner. they take a month off in the summer, more holidays.
so marketplace realities are what they are.
but lots of American audiophiles evolved beyond the brick and mortar brands, but still had more space and options for room space and more disposable income to spend.
smaller spaces and less disposable income did push things to different places.......generally........alternative driver types and speaker sizes, alternative amplification types.