From the post on TechBlog on municipal wifi in Houston, it is interesting to note the problem is the subscriber rate. Not enough people sign up to make the economics of it work. This reminds me of other financial prediction models. From the post:
One major flaw in these arrangements has been that initial forecasts
for Wi-Fi subscriptions used to justify the investment in these
networks have proven to be overly optimistic by a wide margin. In many
cases, 15% to 30% of an area’s population was expected to sign up for
muni Wi-Fi. But only 1% to 2% have signed up so far figures Glenn
Fleishman, editor of an industry blog called Wifinetnews.com.