Slightly different scenario, this is no way a defense of rural or agricultual areas but a theory regarding areas that were once nice and fall from grace as opposed to just an area that is, was and may always be poor. Hillcrest very well could have been next, in the 1980’s it was going to crap, creeping in from North Park (which fit the theory as well) but both benefitted from revitalization, being a little hip and being the gay area is the X factor, that is the antidote to pedestrian ghetto theory. Golden hill was once a nice area too. Having mixed use zoning can go either way. Kensington became hip, while city heights went bad. Downtown was once a mess, then hip and cool, it can always go back up or down. Rancho Bernardo or Scripps has no advantage over any of these areas or any ghetto, in fact climate and location are inferior. they are some of the older examples of this type of planning and I’ll bet it never goes ghetto, while the mixed use areas can go either way in the next 30 years, it’s all about zoning and planning. Or I could be wrong.