Over the last decades the big providers have developed legal strangleholds on municipalities regarding broadband infrastructure. Many (most?) cities are legally restricted on what physical wires they're allowed to permit, per the agreements they've made with comcast/at&t/turner/etc. It's extremely difficult for anybody, even google, to break into the market with new lines.
One day, some day, it'll just be a utility. Kind of irritating that Internet provision isn't just like water or power, which I know is a whole can of worms, at least it would be in this country.