Obviously, babies and very small children need to be protected. We dont' need 'baby missiles' flying about the cabin in an emergency.
I wonder if it would be that hard for the airlines to develop a safe child seat that is custom designed for airline seats? I would think it would be less bulky than the ones parents bring on board. Maybe I'm wrong about that. They could be offered to the passengers at no cost or a smart cost. Just bring something to wipe the seat down and a baby blanket the child is familiar with.