Would be nice, but I think you're underestimating the costs here. Pulling dark fiber to a location and lightening it up is expensive but it's nowhere near the cost related to connecting it to every home around the venue. If memory serves, 80% of a telco network's costs were the last mile ~15 years ago, and I can't imagine the economics have changed that much.
That makes me think that a proper Wifi setup might be a better way to go. The term 'mesh network' comes to mind, but that tends to connote "utopic ideas" in my head...
