As church architects ripped out altars and altar rails, moved or removed tabernacles, in acts of gross vandalism so liturgical musicians ripped the guts out of our liturgical music. Often we have ended up with a parody of Sacrosanctum Concillium, where we sing at Mass, rather than sing the Mass. Where the words of scripture in the Propers of the Mass are replaced by hymns, or feel good songs celebrating "us" rather "Him".
The increased use of strident instruments like the piano or the strummed guitar, like the microphoned voice often overwhelm, dominate or at least compete with the text and the human action of prayer which is what liturgical music; chant and polyphony, are supposed to be. Machines: mics, pianos, even organs don't pray, people do.
The traditional use of music in the west has been to open up the meaning of a particular text, the text not the music is important, the use of a limited musical range, the use of modes emphasise this. The rise and fall of chant is a constant reminder of the basic meaning of Catholic worship: that God became Man so that Man might share in His divinity, that God raised fallen Man to worship him amongst the Seraphim. The chant of the Good Friday Liturgy, for example, is not sentimental, it is restrained, it is not a cry of pain but full of hope, so too the chants of the Requiem Mass.
Though traditional Church music is not itself catechetical, it is worship but it does teach us to worship in the heart of the Church, with the Church.
As destructive as iconoclastic architects were in re-orientating Catholic worship, often literally by smashing the High Altar and replacing it with a Communion Table, and as the Pope has said, altering the dynamics of our worship from looking towards the place of Christ's coming again, the heavenly Jerusalem to turning our worship into "a closed circle", so the musical iconoclasts have created a distaste for the Latin language, often banning it or pushing it to the margins. This has meant at the very least a pretty seismic hermeneutic of rupture, which has all kinds of implications for reading our past, and of the correct reading of Vatican II. It is sad that so many of our full-time diocesan musicians are foremost members of the theological school that delights in proclaiming theological rupture.
Today there is certainly an important place for the vernacular but Catholic Church music is Latin, we need to accept it, some need to get over it, we all need to delight in it and seek to understand it, fortunately now we are beginning to restore that which had almost been destroyed.