I appreciate what he's doing, but I had to look at it twice to figure it out and it's a little disingenuous.
Los Angeles, at least, is done with North at approximately 4 o'clock and there are a lot of big empty spots that are, well, water and unbuildable land and such. The big empty spots in the middle are commercially-zoned. Yeah, you can totally see the dividing line when you go from "shithole around Pico" to "Beverly Hills adjacent" (it's just as stark in real life; rode my bike through there about a month ago and you go ghetto to Kardashian in one traffic light) but my neighborhood (which is just off the image on the lower right) looks pretty reasonably-high income and we had a fuckin' drive-by last week.
I guess it ain't all about the Gini coefficient.