I guess I dont see it so Black & White. Neighborhoods have changed everywhere in the metro areas of the US. Where I grew up people had upper middle class careers and incomes too. They drove normal cars and lived understated lives until their kids hit high school. Soon their kids were driving cars nicer than they had for themselves in many cases. They always had the money they just lived differently as the expectations and tastes that became societal norms shifted.
BTW, if you think the “good” areas in O’side, Vista, Escondido, that are safe, clean and not surrounded by “bad” areas are priced at levels that are pretty comparable to our “exclusive” neighborhoods you are walking around with your eyes closed. I just closed a sale in a nice, safe and not surrounded by bad area of O’side. It was a 3/2 1700 sq ft 1 story built about 10 years ago on a big corner lot with a long driveway, a big sideyard (big enough for good size pool/spa and out door kitchen-it had them btw in perfect condition) and a good sized grassy back yard for kids to play in and had NO HOA or MR. It was in very good condition had the granite and stainless steel appliances. It sold for $350K. Show me a single detached home sale of any type in our area under $450K let alone a house like that which would sell closer to $600K around us.
I’ll send you a link to the house and you can decide for yourself.