I've said it before, but to reiterate there are left handed turners and they turn well.
If you turn on the outboard side of a Graduate, it rotates what to us now, is the wrong way, so you turn left handed.
I've watched them turn from the opposite side of the lathe with it running in reverse (chuck secured in place), and yes it is safe.
I turn with whichever hand works best at the time, from the front of the lathe.
People who insist that you cannot turn left handed are wrong and for those that teach and insist on people turning only right handed are just not prepared to learn the skill themselves.