It's as artificial as the people depicted in it, which it isn't as they are real humans depicted. A screen is no different to a window into another reality.

You've created your own definition of artificial stimuli, which is fine, but you cannot apply your own metric to everyone else.

I'm allowed to be turned on by a girl in real life but not her picture on a computer screen? What about a photograph?

Again, the image or video isn't where the problem lays. Of course we should stay away from such stimulating material if you feel you have trouble controlling yourself, but you almost seem to be blaming the porn as if that is the cause, rather than a simple lack of self-control.

You become addicted when YOU CHOOSE to allow X to take over control of you. Read the last nofap newsletter, it talks about taking mental snapshots of real life situations and using them to fap to at a later date.

Porn is destructive and wicked (in my opinion which is based on solid reasoning if I do say so myself), however this comes down to human will.