My concern is that the bands water down the Gospel and it becomes more of a "feel good" message than a salvation message.
I think this comment of yours is on the mark. When so much of this world is based on Rock Music, enjoy going to Church to get away from it, not to hear a Christian version of it.
What's wrong with rock music?
I think that one reason alot of people have stopped attending church is that the music mixes shallow Christianity with a worldly beat. Then they amplify it so the neighbors a half mile away can hear it. Then there is the 7-11 music: seven word lyrics sung eleven times.
All in your taste. One of the reasons I quit going to the Southern Baptist Church was that I could not stand the music any more. John Wesley adapted English pub tunes to Christian lyrics. All in what you like.
You assume that musical genre, qua rock 'n roll, is by itself sinful and worldly. This is a dangerous assumption to make, since most Christian music and hymnody throughout history utilized music taken directly from the current culture.
The important thing is that the LYRICS glorify God. There is no such thing as a "sinful musical genre."
I would rather hear a song that has doctrinally-correct, God-glorifying lyrics in the rock 'n roll genre than heretical lyrics in a traditional music format.
Christian rock done right, is wonderful. Done wrong, it is pathetic.
Christians that the Lord has so prepared, barge right in and plunder the rock instruments back from the now-bound "strong man" (the devil).