For the same reason there are restrictions on salt licks during hunting season, it would be immoral to just yank the rug all at once. It has to be phased and would never get enough votes to even start in the right direction if that isn't in the wording - reality bites but for most of us it's an inconvenient pest - for some it would be like getting thrown back into the ocean after being rescued.
Excellent comment. I think people have been suckered into dependency, and virtually all of the previously available alternatives have been removed — getting back to a better social contract is going to be difficult and take quite a bit of time.