Russians had an almost neurotic horror of the street-dirt on the bottom of people's shoes, but didn't worry much about the smell of their armpits.

Americans had an almost neurotic horror of armpit-odors, but didn't worry much about the street-dirt on the bottom of their shoes.

(Objectively speaking, neither dirt on the shoes nor stinky armpit sweat is likely to spread any kind of disease -- so in both cases, the "horror" is a culturally-learned aesthetic reaction and has nothing whatsoever to do with logic or medical science.)
Americans are a little over-obsessed with hygiene, I think. We cover up every little odor with endless assortments of sprays and perfumes and candles and unguents and so on... I actually found it a little refreshing in Russia and Europe, not to worry so much about bodily smells.