If I understand it correctly, the two ways that incumbents are able to kill these efforts are through lower costs and through infrastructure restrictions. Emitting radio waves is both cheaper and lower-infrastructure than laying fiber. The question in my mind is whether the quality holds up.
You forgot pay the opposition party to demagogue. Lobbying has a higher ROI and they can keep treating internet service as a luxury good instead of a commodity.
Is the Boston one seeing any progress (admittedly its current incarnation is rather recent)? I am moving there soon and would love to join a mesh network, but from my (superficial) reading of their materials, they do not have yet any nodes you can connect to (as a person not owning roof access for a "super node").