This is helpful:
The main thing you need to do is recognize that this kind of bad gentrification is a relative scarcity issue. It’s very expensive to live in low-crime walkable transit-accessible neighborhoods featuring good public schools because housing in such neighborhoods is in short supply. To reduce the cost of housing in such neighborhoods there are a few things you need to do. One is that where you have neighborhoods with some of those characteristics you need to allow for denser construction of housing units. Another is that you need to work on the social policy problems of crime and school performance in existing walkable urban neighborhoods. And a third is that you need to build more transit lines and transit nodes and ensure that such nodes as exist have “smart” (i.e., dense, walkable, mixed use) development around them. And a fourth is to not waste the opportunities that we have — there’s a giant open-air parking lot right by the Rhode Island Avenue Metro Station in DC, which is just a dumbly low-intensity use of land adjacent to scarce Metro stations.
Long story short, the greatest villains of these kinds of stories aren’t the gentrifiers so much as the folks living in the already very nice areas who’ve tried to “pull up the ladder” and boost their own property values by choking development in the parts of the metro area where they live.