I agree wholeheartedly with the human factor. I also generally agree with the human GM factor, although it is less of a given. A human GM can do many things better than a server, e.g. portrayal of NPCs, pacing a session, adapting to the players' plans on the fly, flexibility in terms of what the players want to do, etc. What I heartily disagree with is the apparently fairly common notion that a DM who constrains himself to follow the rules is somehow less of a DM than one who reserves the right to change them at any time.