I think its more of a matter of class-warfare politics. Cities would rather have nobody have fiber than just the people who could afford it.
Chatanooga's system cost 5-8k per subscriber household for fiber and smart grid. It has resulted in little to none of the projected economic growth. And the revenue stream in no way makes up for the capital investment. The market values the NPV of a Comcast customer at only $2,500, and cable customers pay quite a bit more than $70 per month.