Participation often results the resident's (large) family moving in, with their 4-5 vehicles, increasing traffic (and pollution) and load on local services (daycare, schools, public transport, hospitals, police, fire departments), all while paying the same level of property taxes as before.

Talk to someone living in San Jose or San Francisco about their daily commute on 85 or 101. They somehow don't profess as much love for densely populated urban environments.