It will probably take a generational shift in order for cities to be more interested in building these types of neighborhoods with that kind of density.
One of the main reasons these types of neighborhoods still exist anywhere in the US is because they are usually populated by minorities of national, racial, or sexual background. Walk through the densest parts of Flatbush in Brooklyn and you will mostly see Black/Hispanic Caribbeans, Orthodox Jews, Sunni Muslims, and some Europeans and shops and restaurants that cater to cultures most Americans probably never heard of. Practically a place that is completely different from the rest of the country that identifies itself with the least diverse suburbs and more independence with big name stores on large parking lots and single family homes in gated communities.
Aside from the regulations that prevent old-style walkable places from being built, the majority of Americans still don't desire to live in the city. Even if they wanted to, cities are now becoming increasingly expensive and the vast amount of resident units are only available to those who are higher than middle class.
I think that in the future the US should adopt a widespread development style that will focus on catering to both urbanites and suburbanites:
Existing major cities( mostly cities in the Sunbelt and the Rustbelt) around the country should continue to become dense by building infill and relying on immigrants and lower class people( or lower class yuppies or college grads) who have not been entirely corrupted by "car culture" to live within the city and give it some traditional urban character that would support mass transit and density. The ultra rich can continue to live in the CBD, but the rest of the city should be middle to low class people who are not dirt poor but are willing to give life to the city like we see in the major urban areas in the country. The demand of those people to live without a car either because they can't afford one or don't want one should power the demand for many lowrise residential and commercial buildings with little parking in the form of parking garages or underground or no parking at all. If parking must be needed for outside visitors who live in the urban area, park and ride systems should be rampant around the metro area's suburbs, which goes on to the second part of my plan...
Suburbs can continue to grow and expand. However, they have to be more dense and have a similar walkable environment to the old streetcar neighborhoods with sidewalks, parks, and some connection to public transportation. Strip malls would decrease most of their existing parking lots and suburban areas with long stretches of wilderness in between should be the focus of more development if it is environmentally safe to do so. I'm sick and tired of walking through "green ways" that serve no purpose but are in between two nearby areas of interest. Those random plots of swamp are rampant in the South, especially in Atlanta and Miami suburbs. Luckily, separate suburbs with good densities will be connected by commuter rails through many "park and ride" stations that will form a "wheel with spokes" around the central city, or a"ribbon", depending how the urban area is shaped. The older suburbs will become more urban first, which should be the focus of more walkable development. The exurban-type sprawl can be there for those people who really love their cars and space and can afford it, but those places will not dramatically increase in growth, thus sprawl will be regulated near existing suburbs that surround the central city.
In all, that's just my take in it. Sorry for taking this thread a bit out of topic, but I feel that this should be the mode of development for the nation since America can never be like Europe, but we need to limit our unsustainable appetite. This vision doesn't completely forget about the car, but it focuses and trying to bring the car in equal footing with the ,bicycle,bus, train, ferry,etc as the majority of our cities start to put the average pedestrian first in the core, and build everything else to cater to many different people who live in the US, who are largely the diverse middle class people that have made this nation great.