But why?
If you're concerned about safety, you'd prefer an out-of-control drone hits a car instead of a backyard or farmer's field?
And if you're concerned about noise, homes tend to be along roads anyways. So it's not going to change that.
And FYI, they're basically always below 500 feet, so they don't hit planes.
I believe that they were responding to this specific part of your comment:
> But the idea that drones must keep track of which individual properties allow flight above and which don't, and try to navigate some around some kind of patchwork accordingly, is simply unpractical and unreasonable
Flying over public roads would be a way to avoid flying over properties that do not allow drones and would not be unpractical.
OK, but the point is, it doesn't fix any problems either.
But it does create them, if drones have to travel 2x as far by following roads, which wastes energy, limits range, and requires flying more drones to achieve the same level of e.g. deliveries.
The larger point is that property owners don't have a legitimate reason to ban drones passing 200 ft over their house. If they're bothered by noise, why are they going to be any less bothered because the drone is flying 50 ft away over the road at the end of their driveway? If they're worried about drones falling out of the sky, they're still going to be bothered about their car being hit during their entire morning and evening commute.