They are,especially toddlers.Once under they can't get there head above water without a foothold.
I want to add ,yet another personal point.Please,no sorry posts .
My then,16 yr old daughter ,found my 15 yr old son after he committed suicide. She and my husband had to get him down (he hung himself) and immediately started CPR,then DD called 911. DH continued CPR until paramedics arrived. I won't go into detail,but my son had probably been gone for a short while,but it never occured to DH not to try .
I was waiting at the entrance to the ER when the ambulance pulled up.
My child was rushed in ,and very shortly thereafter dr came out to tell us there was nothing he could do.I begged him to go back and try .Just keep trying to bring him back. To not continue was not an option . I know now ,he was long gone and there really was nothing anyone could do.
When I was a pre-teen a family from our Parish lost a toddler in a horrific accident. They received a delivery and as the truck was backing out it ran over the child,who was nearly decapitated. Several kids saw it and quickly the story spread of how his mom ran out and picked him up,putting his head back in place. He was clearly dead,but as a mom,you just can't go there.You have to try ,to fix it.
I'm sure it's our brains way of protecting us from the sudden shock.To do nothing ,absolutely nothing,to try and save your child makes no sense.
That's a big hole in the defense scenario.