Yeah that’s a huge part of it. Few Americans (me included) frequently walk outdoors on anything but sidewalks or paved roads in their normal day to day travels. When I go hiking I take those shoes off before I get back into the car, but my daily driver boat shoes which rarely touch actual dirt? I don’t have a problem leaving those on in most places, my house included. Same I imagine for Americans where their job is construction or something where your shoes are dirtied, take the work shoes off when you get home, but it’s fine to wear more casual shoes

Edit: what a strange thing to get downvoted about

Double edit: I guess the first downvotes were just from people who very much don’t like shoes in the house under any circumstances. That's ok. If I come to your house my shoes will come off. If you come to mine, feel free to leave them on if they aren't muddy.