The critics are not very bright for several reasons.
For one, you do not just walk up to a 400 lb. gorilla and say “OK, let me have him”.
I know nothing about gorillas but I do know that almost every “A” type animal will defend his prize.
Just try taking his bone or a freshly caught rabbit from an “A” type dog.
Our dog is not a big dog at all. She is just a little larger than the large beagles, but try it with her and you will be counting your fingers to be sure you still have all of them.
Whereas that gorilla was maybe playing with the child, I would bet that he would be very difficult to deal with if one tried to take the kid away from him.
Both the kid and the rescuer would have been hurt and probably fatally.
Brings to mind the movie "Baby's Day Out".