NIMBYs want to increase the value of their land. If they rented land from the government at a market rate, they would want to lower their rent by lowering the cost of housing. We must increase public housing to align people's desires with the common good, or else they'll vote for bad city planning.
The value of a building is influenced by its surroundings. By creating a cheap crappy building in a good location, you can inflate your land's value, but it will lower the value of surrounding land. Construction must be centrally planned to avoid this.