I read an article recently about the idea that versus populum is a manifestation of clericalism. Clericalism, if this is not a common term for you, is the over-eageration of the clerical (bishop, priest, or deacon) state to a level of pridefulness.
The article contends that in the versus populum style of the Mass, the priest is placed as the important piece of the Mass. He is central; he is indispensable. As with the picture below and as it had happened in many churches after Vatican II (with no instruction or indication to do so), the tabernacles were moved from the central area of the altar to some off the side place. In the place of Jesus Christ, truly present in the consecrated Eucharist in the tabernacle, the priest put his own chair, placing himself as the central point of the sanctuary. I think the claim is not unfitting to say that this is very egotistical to remove Christ and place oneself in His proper place.
The article also touches on the idea that priest can be anonymous, as he acts in the person of the one and only High Priest, Jesus Christ. For this reason, the priest isn't really important in an ad Deum Mass; you don't have to see his face. It is a humility, as we've been praying this month in the prayer before Mass (the litany of humility), to be forgotten. You don't have to know the name of a single priest your whole life long...you can just call him father. In fact, you may have never met him before, and you can walk up and start off any request with "father, I was wondering if..."
The ad Deum Mass preserves this humility. As the priest, I am not separated from people of God on the other side of the altar; I come from the doors (which I serve you by holding open) to stand with you before God. As the priest, I am not directing your attention to me, me, me; I am turning my own attention with the people of God towards the Rising Son (the East). As the priest, I am not severed from the Body (the Church, the faithful) and turned against (versus) the Body; I am the head with the mouth to speak the prayers and adoration to God the Father, on behalf of the whole Body and for the good of the whole Body. This last part reminds of St. Paul's first letter to the Corinthians (ch 12): we are one Body in Christ -- let there not be divison.