Actually, the Pope makes clear the liturgy is FOR us, (primarily) BY God.

Adam said:

So, if it isn't for us, should we just stay home and let the priest handle it?

As I understand it, God celebrates the Mass for us (through the priest and through us) for the expiation of our sins. I would think the least we could do is show up to offer praise and thanksgiving for so great a kindness shown to us.

The way this is viewed certainly has consequences on the music in the Mass. If the Mass is thought to be about us primarily then the music will be about us, about the me and the we, just like the hymn I recently heard sung after communion, "I come with joy". But the Mass is more than a mere social event.
The Gregorian Propers of the Mass are rarely if ever about the me or we. Could this be another reason why they are so unpopular?
And the way this is viewed also delineates the meaning of "active participation". When the liturgy is celebrated primarily for God, God comes to us by His grace. If the Mass is primarily about God, then active participation is primarily internal and spiritual.

"...the Pope explained how the Church is made most visible in the liturgy, where “God enters into our reality, and we can meet him; we can touch him.” The liturgy is where “he comes to us, and we are enlightened by him.”

The Mass is offered to God the Father by Christ the Son, on our behalf. Like Adam said, it is for us, but not about us.

Further, the ecclesiology of the Eucharist can also be described as Christ's offering of His body, of which we are a part. That is why the priest acts in persona Christi Capitis Ecclesiae: in the person of Christ, who is the head of the Church.

"Man was made for the sabbath, not the sabbath for man."

Gavin, did you deliberately get that backwards?

Quia, cum nostra laude non egeas
tuum tamen est donum quid tibi grates rependamus
nam te non augent nostra praeconia,
sed nobis proficiant ad salutem
per Christum Dominum nostram -- Praefatio Communis IV

For although you do not require our praise,
By your gracious gift you enable us to give you thanks,
Not that our praises may increase your glory
But that they may avail for our salvation
Through Christ our Lord

Mr Wood:
The Mass can be "for us" without it being "about us."

Benedict XVI:
"The liturgy is celebrated for God and not for ourselves.”

Benedict is not primarily speaking about benefits here; obviously we can have benefits for our salvation from praising God at Mass as a consequence, if God so wishes.

The point Benedict is making is that too often what the people want at Mass is put ahead of what God deserves at Mass. It that sense, I do not see how a Mass celebrated for us will not be about ourselves. Has not this Copernican liturgical turn been the chief problem since the last century, that of serving first the people at Mass rather than God? Otherwise, why turn around the altars and bring in the anti-sacred pop music that delights the common masses, while leaving little to endure in the soul? The Mass is not about feelings, which are ephemeral. In serving God first, we bring into the liturgy the best that is humanly possible to praise God with. (Yes, that means good choirs.) From there, the grace of His presence can obtain. His presence can be discovered in the Holy that the liturgy, including its music, is meant to unfold in front of us. The Holy is beyond the rational, the understandable. It is also well beyond "feelings". Rather, the Holy directs our passions towards God. The music at Mass must be Holy. The Gregorian composers certainly were aware of this.