Here's the deal: prior to the great building boom of post WW2, architects designed neighborhoods, individually. Study any of the old master planned communities and there's an architect that sites and crafts each home. Other reasons why the neighborhoods are great: they're spaced around street-cars, so everything was very compact; everyone walked, so there were shade trees and sidewalks on the inside of the landscape buffer; because everyone walked, there wasn't an auto-centric design to the subdivision and streets were narrow causing very little through-traffic furthering pedestrian orientation; these suburbs were located very close to urban centers, so they've retained their real estate proximity to amenities, jobs, shops, etc.; and lastly, those suburbs were eclipsed by other, bigger 'modern' suburbs (and the war) that limited further production and expansion of these pre-war suburbs. As we all know about real estate, as supply goes does down, demand increases. And so, these pre WW2 suburbs (which probably weren't always nice, ala 1950s with white flight), became the most well-crafted, designed, unique places to live that were conveniently adjacent to an urban center. Now, those elements are undeniably attractive, but are also very expensive. There are lots of similar vintage suburbs that aren't located directly to downtown or have access to amenities, so they never retained their real estate value; thus, no one invested into their homes and the neighborhood (as it aged) slide into disrepair. It's ironic, but the simple economic engine of real estate (buy house, fix it up, gain value) also causes social justice issues to those were are not able to increase value in their homes and then 'sell-out' as the neighborhood increase in value and move to less expensive areas. On the one hand, we like really upstanding neighborhoods with pride in ownership; on the other, we hate gentrification. But of course, they're part of the same economic/real estate process.