Bah. I call BS. You sound like a San Francisco real estate speculator or developer. "High density infill" projects are loved by the people who make money off the development of the property but no matter how much you weaken zoning protections to get there they somehow never manage to swing prices when demand, like it is now, is just so much greater. What you do accomplish with these projects, typically, is building very high-end price units, often of compromised quality (cheap materials, absurd square footage, etc.) Of course this does have the effect of reducing gentrification. On the contrary it steps up the pace while simultaneously leaving the city with a less desirable housing stock in the long run.