When I'm traveling, if I ask the hotel staff to recommend any restaurants "within walking distance", they'll grimace and say there aren't really any, even while Yelp informs me that there are six within a kilometer.
Yesterday I ended up spending about 15 minutes waiting for a bus that was late. Someone else spent about the same amount of time as me waiting on that normal street corner, and then got back off the bus about 5 blocks later. So, that makes ~15 minutes standing around waiting for the bus and $2.25 spent on a fare, in order to save a 5 minute walk. I assume they're at least as able-bodied as I am, because, unlike me, they didn't opt to sit on the bench during the wait.
I just don't think the US has a culture that considers feet to be a valid mode of transportation.