Cell phones and driving

I don't understand why there is a single US state that allows people to talk on the cell phone and drive. You are maneuvering usually at least a 2000 pound machine down the road surrounded by other machines, some of which are a lot larger, and the laws of physics mandate that you can't occupy the same space with any of them at the same time. If you inadvertanly try, then the result is an accident. You need both hands on the wheel and your attention centered in a 360 degree direction. All distractions need to be minimized. Even talking with another person in the same vehicle can be a distraction; how much more so can that be talking with somebody you can't see? It's a recipe for disaster. I've even seem some of the dumbest cell phone behaviors, more so by woman, i.e. backing up and talking on a cell. If you need to make a phone call call the person then hang up and back up, drive, and be safe. This applies even more so to texting and driving. If you're not willing to practice good driving habits, you shouldn't be on the road.