I agree with this post on so many levels, but at the same time...
... as a convert, that music spoke to my heart. I really had the simplest of faith, one that really had no head knowledge, hardly any scripture knowledge. God called, I listened, and this simple music that I found on my local Christian radio station fed me in many ways in the early days of my conversion.
...as I grew in faith, I also grew in appreciation of liturgical music, Taize, Gregorian Chant, (right now I have the Liturgy of the Hours in song (Benedictine). Do I listen to this constantly?. No. But I certainly use some of this music in my prayer time and my heart responds to this. I never listen to Christian rock on the radio anymore, but when I do hear that music, the repetitiveness, the sugary messages repel me.
... as I began to minister to others in the field where God planted me, really different music began to be a teaching and guiding tool. Catholic praise music, Catholic rap, Father Stan Fortuna, for one, has been an amazing door for some of these broken hearts to receive the Church as their home. Some of the music by the band Zealous, for example, is beautiful Catholic, but the "style" of the music would be offensive to some people who prefer only orthodox or sacred music. Check out some of their lyrics... (which I found on their website)
Go and make disciples of all nations
Even in the face of raw hatred
God has always used inadequate tools
So don't think he can't work with you
Recently, people, are causing, you grief complete
With enough drama, that you, think you'll meet defeat
If the mountain, that you're climbing's, too steep to beat
You’ll find it's not, quite as steep, as it seems to be
State of the culture, to me, is indecency
I don't know how, you're not able, to see deceit
It doesn't matter, the fact, that you're weak in speech
Rise up, expose the truth, that the world, needs to see
Light up a fire, of faith, that'll heat the streets
Spreading so rampantly, can't barely, feed the beast
The new faithful, learn the creed, sayin we believe
Till all the demons, start shriekin, and flee the scene
Follow with faith, like a child, so you're breathing free
Never look back, and dive into, the heathen sea
Jesus chose Peter, and gave him, the keys to keep
Made an unworthy man, worthy, to lead the sheep
Those are interesting lyrics in the context of the demographics that this group sings to.
I do not in any way believe this kind of music is appropriate in a liturgical setting. But, as John Paul II has called all of us to build up the church through Evangelization, I think we have to at least try to understand the language of the people we are trying to bring God's love, hope and mercy to.