I agree with Joan here, communities aren’t fungible. Building something where something already exists does carry a cost. But I can also see how this will be used as one more arrow in the quiver of NIMBYs. In addition to environmental, economic, political reasons not to build something, also consider the cost to potentially breaking existing community bonds. We shouldn’t build new high density housing because the new…
Also, the article touches Moses, right, but it is about communities as a concept, with a heavy emphasis on online communities, where 'new things to buy' do not come at the expense of 'tearing down the old' - and where, when you tear down the old, behaviour patterns change. Take, for instance, the reddit re-design, which changed the page's culture. Or usage patterns of RSS post Google-Reader-shutdown.