I'm not sure when it started per say. I just think its really odd how you have this pocket of very high income people and no one is bothering trying to cater to that demographic, but instead to the demographic that cleans their house or mows their yard. E.g. the flats of beverly hills fill with taco trucks during the work day specifically for the housecleaners and landscapers to get their lunch. Maybe this high income class of people just puts on very low demand for goods and services relative to lower income classes of people.