That complete lack of walkability is some serious riff-raff proofing they're doing there. Can't have anyone without a car just wandering into a nearby pleasant little suburban cul-de-sac now can we? You see, lack of walkability is basically a strategy for keeping poor people out of nice areas. San Francisco is the exception to this rule because of the hills. Poor people don't like to walk up hills to go to the liquor store ergo nice houses can be near poor neighborhoods as long as they are sufficiently up hill.