It is rare, in the US at least, for any representative or direct democratic situation to ask for
unanimous consent. Someone will almost certainly disagree once you get past 1 voter (or one representative), and possibly they'll disagree with themselves.
What's interesting about this case is that the municipalities have made moves towards this with their own money and efforts. And it is the state which is attempting to squash it, that is those around them. It would be as if you said to your neighbors, "I'm going to try and do something which will have zero impact on you, like eating more vegetables that I grow at home." Then they all gang up on you and deny you the right to grow and consume your own vegetables. If the action were harmful to you and your neighbors, like say you decided to make meth in your home, then it could be a reasonable response.
What about municipal broadband causes harm to those outside the community which wants it such that their representatives in the state legislature have any reasonable standing to try and bar it?