I think we've avoided one thing that really makes this issue relevant to a bicycle forum--maybe just because the issue is so obvious it doesn't need stating.

Large houses on large lots are one contributor to sprawl. When houses are further apart, as when there are 10 housing units per mile of frontage in an upscale exurban subdivision, as opposed to hundreds of units per mile in a moderately dense urban area, all destinations are much further apart. This is very inconvenient for bicyclists as well as pedestrians and bus route planners.