Frankly I think you'd find a lot of people would happily move into denser areas if they were more pedestrian friendly.
And so much of the sprawl in the US is not about residential housing taking up lots of space, but about separating shops and other essential parts of infrastructure from housing in a way that is only tolerable because of the car culture.
E.g. I used to travel to Palo Alto and Menlo Park a lot for business a few years back. I don't have a drivers license, so I experimented with how possible it was to stay at various hotels while walking as much as possible (didn't want to depend on co-workers or cabs to get everywhere, and I like walking).
At one point I stayed in Atherton and walked to/from offices in Menlo Park. People probably thought I was pretty crazy, but to me the distance was no more than what I'm used to, and the "commute" length was shorter.
But what got me was the structure of these - by US standards - quite reasonably pedestrian friendly small towns. If you lived right next to Menlo Park or Redwood City or Palo Alto town centres, a lot of things would be within walking distance. But basics were missing. Such as grocery stores. I soon learned to pick hotels in suitable locations to be within walking distance of somewhere where it'd be possible to actually find a decent selection of food nearby (eating out every day gets boring surprisingly quickly).
On top of the distance, the pedestrian friendly areas were "islands" not linked in any reasonable way. E.g. from Menlo Park to Atherton or Redwood City it seemed to me I had the choice between walking down El Camino Real, including a long stretch with pretty much no roadside lighting (fun walk back late evenings) and no sidewalk (for those unfamiliar, El Camino Real is one of the main roads in the area and heavily trafficked), or taking a huge - 3 times the walking distance or so - (but scenic) detour through back roads past Atherton estates.
(Amusingly, as I tried the backroads through Atherton, everyone I met greeted me as I walked past. It seemed like people assumed I must belong there, because why else would I be walking there? (I'm used to people being more friendly in California than I'm used to from London, but this was a huge step up).)
This is not about density, though density helps, but about a culture where everything is centralised because everyone drives, and where everyone drives because everything is centralised.