This is definitely an important part of any solution to revitalizing cities and I hope it doesn't get overlooked. Our cities are dead without the PEOPLE who live in it. Truly caring about a community, I think, starts with truly showing care for your neighbors and fellow citizens.
It's too bad so many newer neighborhoods are carelessly designed in ways that inhibit interaction with neighbors.
Conflicts that often arise between neighbors (noise, etc.) might be avoided if we get to know each other more and become more understanding of each other.
Neighborhoods that have a strong connection will be stronger in keeping their neighborhood alive. They might find they have similar desires for improvements and when those desires are discussed they are more likely to happen.