Regarding lethality, I don't quite get the complaint about the swords... it's not like Donna and Diana can't rip tanks apart with their bare hands?
I do however get the complaint that the sword is perhaps not really needed since (I might be wrong) Diana doesn't seem to actually use it that much in actual fights. So perhaps it's to be seen more like Batman's utility belt; as an option.
It goes beyond that, there are people who believed the same thing happened to comic Terra, that somehow Deathstroke got in her head or that if she hadn't freaked out and killed herself, then she could have been turned around. It's why W/P later brought in her alternate timeline self.