Why downvote parent? A human is a "natural" predator just with different methods of attack/more intelligence than "animals". Why is a human predator (an "apex predator" if you will) any less "natural" than a T-Rex? Or any other animal that forced evolutionary change?
Because of civilization. While the word "artificial" is certainly overloaded, this is basically what we've designated the word to mean. That's not to say a human couldn't be a "natural" predator, if you assumed an isolated tribe, but that's certainly not what's happening here. If we call this natural, there is no longer any meaning you can ascribe to artificial.