I don't think it's people just wanting to live in 'popular' neighborhoods, but safe neighborhoods. In the places you're describing you don't go out after dark, crime is common, and you also get to enjoy things like SUVs slowly cruising around at 1am with sound systems more fit for a stadium than a car.
In places, like most countries in Asia, where crime rates are vastly lower, you'll see far greater levels of socioeconomic mixing with defacto mansions near rather modest houses. The same is also true to some degree in rural areas in the states, where you'll see a trailer on a couple of acres with a truck husk or two in the front yard right beside a house that you'd be more inclined to call an 'estate.'
In places, like most countries in Asia, where crime rates are vastly lower, you'll see far greater levels of socioeconomic mixing with defacto mansions near rather modest houses. The same is also true to some degree in rural areas in the states, where you'll see a trailer on a couple of acres with a truck husk or two in the front yard right beside a house that you'd be more inclined to call an 'estate.'