This is misleading. 34 new cities in 9 metro areas are being evaluated for Google Fiber. This is far different than Google planning on delivering fiber to all 34 of these cities, like the article makes it seem.
Likely current infrastructure along with receptive local governments. Some cities/major metropolitan areas may have special contracts with ISPs to only allow them to sell service to their area. I know that Comcast has a serious hold of the Midwest with AT&T trailing behind and Time Warner Cable has the Northeast.
Apparently it still is not a better business proposition for Big Content to buy their own network.
At some point, Big Network's disinterest in being a network provider) will force Big Content or (heaven forfend) Big Government to move into the network space.
Here is the information directly from Google: https://fiber.google.com/newcities/