Earlier quoted context omitted.
As soon as drones are required to have geofencing, you will find they become useless for monitoring the police, factory farms, pollution, "black" sites, etc. Humans die because of those things, while no practical benefit to aviation safety has been proven. And yeah, controlled airspace has been used to prevent monitoring of police, in Ferguson, for example.
Another slippery slope argument. We're talking purely about controlled airspace here. Those things you mention have never been controlled airspace.
"We need to do this or that because terrorism and won't somebody please think of the children."
"Well, now that it's in place, it would be a shame not to use it against illegal ."
And usually they manage to design laws so that diverting their use doesn't require passing through parliament again.