On the other hand, if all the twenty-something professionals were allowed to live in the city center of their dreams, with Paris-like population density, and hipster cafes and restaurants in each city block, there would be more room for the suburban sprawl for the families to be closer to the city center.
When the "suburban party" denies the "city hipsters" the dense, walkable neighborhoods, they also force the hipsters to compete for the same suburban estate, which drives prices up and commutes longer, and everyone is worse off as a result.
People who want X for themselves, would actually benefit and get their X cheaper and better, if they allowed other people who want Y get and build their Y, instead of forcing everyone to compete in the market for X.
I bit unintuitive, I understand.