There is a tradeoff between freedom and community.
Organic bonds with real feeling come from a true alignment in interests. One of the simplest ways of creating interest alignment is making sure everyone has a long-term commitment. But the flip side of 'commitment' is that people can't be free to leave whenever they want.
A highly mobile society where everyone is largely free to join or leave any virtual community, neighborhood, is one where nobody feels any form of permanent attachment to that institution or to their fellow community members, because there is no long-term commitment, either from themselves, or from their fellow members. A neighborhood where everyone has the ability to freely come and go is one where nobody has a strong incentive to sacrifice for their neighbors, because who knows who your neighbors will be tomorrow, or whether you will still be there?
You can see one aspect with the rise of no-fault divorce; in the past, perhaps many people were trapped in unhappy marriages, but by the same token, the lifelong commitment may have encouraged many couples figure out ways to make it work. Nowadays, it is no longer possible for both members to bind themselves to one another. And since both partners can walk out at any time (and both people know it), why go to extraordinary lengths to make it work?