Well, because the way that mesh networks (at least mesh-toplogy networks) function is to route packets to neighbors. Nodes don't blindly and neutrally route packets along; they select specific packets to route to specific neighbors.

Any useful network uses routing. Comcast is not defying net neutrality by delivering all the packets addressed to your IP to you. Net neutrality is not breached until Comcast or your mesh network starts handling the packets differently based on who they came from and the business decisions about that source.

Right, sure. But on a bus, routers blindly route all packets. They don't discriminate.

On a mesh (at least in OSLR or BATMAN), nodes only route certain packets. They are also free to drop packets for any reason, be they geographical or economic. Nobody can demand that a node perform routing.

I can absolutely imagine a malicious regulator claiming that the law requires every node on a small-town mesh to cart Fox News to the other side of town with just as much priority as packets originating from within the town. And that's not really sustainable for a mesh.