Frequent commenter Melody asked about this a bit earlier. I’ve seen it on Facebook and at PrayTell. So a few things come to mind.
First, the hosting organization is solidly in the traditional/pre-conciliar camp. So if Cardinal Sarah gets “prolonged applause,” you can bet it’s not from a British happy-clappy crowd. The CDWDS head was addressing a group of like-minded clergy. Not the Church.
Second, given number one, this was not a curial document, a papal encyclical, or anything in between. This is the opinion of one man offered to a receptive audience. The recommendation given was for those in attendance.
Third, it is possible for the Church to focus on both liturgy and evangelization, mercy, or what-have-you. The challenge is for people on the fringes of the Body. Priests turning their back to the assembly and taking the time to explain it is a distraction. While Cardinal Sarah states a strong desire for the liturgy to be about Christ, the switching of liturgical custom is indeed a human thing. Things like repositioning priests, tabernacles, and candlesticks are not readily perceived as focusing on Christ, except by the people who like such things.
In defense of those who would want to face in one geographical direction, it does offer a symbol of a journey. Everybody facing the same external direction is good for a pilgrimage. Priest in front. Everybody in line behind. Sometimes, though, the clergy belong amongst the flock, and sometime on the fringes.
The Church must also be clear that when people are gathered around an altar on two or more sides, they do indeed face the same direction. At the center.