Because there would be an elevated structure destroying their cities, forming a horrible "great wall" dividing their towns, etc., etc. Like I said, if they think it's so rotten, let them pay for the cost of hiding it locally. They're the lucky ones, in that they'll live near enough to the system to be able to use it and get the benefits. It's the people living beyond the system's core who will be paying for it (through taxes to repay the bonds) but only getting very indirect benefits from it.